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Classifications

Harrison's Part

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Inheritance

1

Autosomal dominant inheritance HP:0000006

NEDDFL results from a heterozygous loss-of-function allele of BPTF; the gene is dosage-sensitive and a single null allele is sufficient to cause disease. Most reported variants arose de novo, but transmission from a mildly affected parent has been documented in four families, establishing autosomal dominant inheritance with variable expressivity rather than exclusively de novo occurrence. Transmitting parents range from isolated microcephaly without reported developmental delay, through learning disability with independent adult function, to a phenotype comparable to that of the proband. Penetrance has not been quantified.

Autosomal dominant inheritance Expressivity: VARIABLE

Show evidence (3 references)

PMID:28942966 SUPPORT Human Clinical

"we report eight loss-of-function and two missense variants (eight de novo and two of unknown origin) in BPTF on 17q24.2"

Establishes heterozygous, predominantly de novo variation at a single locus as the molecular basis, consistent with autosomal dominant inheritance.

PMID:33522091 SUPPORT Human Clinical

"Our study has also uncovered four cases of inherited BPTF variants, providing some insight into the penetrance and expressivity of NEDDFL."

Documented parent-to-child transmission confirms dominant inheritance and demonstrates that the disorder is not exclusively de novo.

PMID:33522091 SUPPORT Human Clinical

"The histories reported in these patients and the presence of inherited pathogenic variants in BPTF do suggest a pattern of variable expressivity in NEDDFL."

Directly supports the recorded VARIABLE expressivity of the dominant allele.

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Discussions and Knowledge Gaps

2

How do developmental NURF subunit composition and compensation determine the consequences of heterozygous BPTF loss in human cortex?

KNOWLEDGE GAP OPEN bptf_vs_smarca1_dosage_paradox

Attached to

pathophysiology#Impaired NURF Chromatin-Remodeling Activity

The original brain-size contrast was based on Smarca1 exon-6 deletion mice that express an internally truncated protein, rather than a complete null. The 2025 study found near-normal cortical size after complete Smarca1 loss and severe hypoplasia in Bptf conditional knockouts; double mutants were no more severe than Bptf loss alone. These results support a model of ATPase compensation and variant-dependent interference. Compensation was tested biochemically in cerebellar CERF complexes because specific BPTF antibodies were unavailable, so NURF subunit switching in cortex remains partly inferred. Its quantitative relationship to human BPTF heterozygosity remains unresolved.

Proposed experiments

Side-by-side cortical comparison of Bptf and Smarca1 conditional knockouts

bptf_smarca1_side_by_side_cortex

Compare heterozygous Bptf loss with complete and internally truncated Smarca1 alleles in matched cortical cell systems, measuring NURF composition, target expression and neuronal differentiation. Existing mouse single/double-knockout comparisons provide the complete-loss baseline.

BPTF and SNF2L chromatin co-occupancy mapping in cortical progenitors

bptf_snf2l_cooccupancy_map

Map BPTF chromatin occupancy in cortical progenitors and ask what fraction of BPTF-bound sites are also SNF2L-bound, to quantify the size of the NURF-independent BPTF binding compartment.

Test whether the BPTF-MYC axis accounts for the Bptf-specific microcephaly

bptf_myc_axis_microcephaly_test

Test whether the NURF-independent BPTF interactome, including the MYC cofactor axis identified by RNA-seq binding-site enrichment, accounts for the microcephaly that Smarca1 loss fails to reproduce.

Show evidence (2 references)

PMID:41213919 SUPPORT Model Organism

"Taken together, these data reveal that proper cortical development requires NURF, and that Smarca5 fully compensates when Smarca1 is completely ablated (no difference in brain size in Smarca1 KO) but not when some SMARCA1 protein is produced (e.g. Smarca1ex6del mice)."

Distinguishes complete Smarca1 loss from the internally truncated allele underlying the earlier macrocephaly contrast.

PMID:41213919 SUPPORT Model Organism

"The switch to the cerebellum and analysis of the CERF complex was chosen for three reasons: (1) the lack of commercially available antibodies specific to BPTF for analysis of the NURF complex; (2) the Smarca5 cKO and Smarca1ex6del mutant animals show similar differential effects on cerebellar..."

The biochemical experiment measures CERF composition in cerebellum, so it is indirect evidence for cortical NURF switching.

Which cortical consequences of complete forebrain Bptf loss also occur in heterozygous mouse or human neural systems?

HUMAN MODEL MISMATCH OPEN bptf_mouse_homozygous_vs_human_haploinsufficiency

Attached to

pathophysiology#Cortical Hypoplasia

Human disease usually involves heterozygous BPTF variants, whereas the major cortical model deletes both alleles in the Emx1 domain. Gross heterozygous effects are limited, but increased cleaved-caspase-3 staining at P7 was reported, so absence of all heterozygous phenotypes is not established. Conditional-null findings include reduced cell-cycle exit, neuronal apoptosis and altered layer-specific neuronal marker regulation. Their magnitude and relationship to human disease remain unresolved, and actual protein dosage should be measured rather than assumed to fall by exactly half.

Proposed experiments

Deep cortical phenotyping of Bptf heterozygous mice

bptf_het_mouse_deep_phenotyping

Quantify cortical volume, neuronal marker distribution, apoptosis and progenitor cycle exit in heterozygous mice, with direct Bptf protein measurements and age-matched controls.

Isogenic heterozygous BPTF-null human cortical organoids

bptf_het_ipsc_cortical_organoid

Derive isogenic human iPSC lines carrying patient BPTF null alleles in the heterozygous state and assay cortical organoid size, progenitor cell cycle length, and deep-layer neuron output against isogenic controls.

Cross-species BPTF dosage-response comparison

bptf_dosage_response_cross_species

Compare BPTF dosage-response curves for NURF assembly and target-gene expression between mouse and human cortical progenitors, to test whether the human system is simply steeper.

Show evidence (1 reference)

PMID:35604347 SUPPORT Model Organism

"To model the NEDDFL syndrome, we generated forebrain-specific Bptf knockout (Bptf conditional Knockout (cKO)) mice."

Identifies the model whose homozygous conditional-null design is the source of the mismatch with the human heterozygous disorder.

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Pathophysiology

11

BPTF Haploinsufficiency

Mechanism confidence: Established

Heterozygous pathogenic loss-of-function variants reduce functional BPTF dosage. The clinical and genetic evidence supports haploinsufficiency, but it does not establish an identical 50% protein reduction for every allele or tissue. BPTF is shared by NURF complexes containing either SMARCA1 or SMARCA5; the consequences of human heterozygosity cannot be equated with complete Bptf loss in mouse forebrain.

BPTF hgnc:3581

Animal models

Constitutive Bptf-null mouse embryo Mus musculus perturbs Perturbs Bptf through complete loss, providing an essentiality comparison for the human heterozygous disorder. It does not quantify a heterozygous dose-response relationship.

Downstream

Impaired NURF Chromatin-Remodeling Activity Reduced functional BPTF is expected to impair NURF-dependent chromatin regulation; the amount of assembled complex in patient neural cells has not been quantified in the cited studies.

Show evidence (2 references)

PMID:28942966 SUPPORT Human Clinical

"our data demonstrate the pathogenic role of BPTF haploinsufficiency in syndromic neurodevelopmental anomalies and extend the clinical spectrum of human disorders caused by ablation of chromatin remodeling complexes"

States haploinsufficiency as the disease mechanism.

PMID:33522091 SUPPORT Human Clinical

"Haploinsufficiency of BPTF in humans leads to the clinical entity known as neurodevelopmental disorder with dysmorphic facies and distal limb anomalies (NEDDFL, MIM#617755)."

Links reduced BPTF dosage directly to the named clinical entity.

Impaired NURF Chromatin-Remodeling Activity

Mechanism confidence: Provisional

BPTF is the chromatin-reader subunit of NURF, which can contain SMARCA1/SNF2L or SMARCA5/SNF2H. Its PHD finger recognizes H3K4me3 and its bromodomain recognizes acetylated histones. Biochemical evidence links histone recognition to NURF recruitment and remodeling. The 2006 recruitment experiment depleted H3K4me3 rather than modeling a heterozygous patient BPTF allele. Mouse genetic comparisons support different developmental roles and compensatory capacities of the NURF ATPases; direct NURF subunit exchange in human BPTF-haploinsufficient cortex remains unmeasured.

ATP-dependent chromatin remodeling GO:0006338 ↓ DECREASED

BPTF PHD finger reading of H3K4me3 GO:0140002 ↓ DECREASED NURF nucleosome sliding GO:0140750 ↓ DECREASED

Downstream

Dysregulated Developmental Gene Transcription Loss of NURF-mediated nucleosome remodeling at developmental promoters changes the transcriptional output of those genes.

Show evidence (5 references)

PMID:28942966 SUPPORT Human Clinical

"Bromodomain PHD finger transcription factor (BPTF) is the largest subunit of nucleosome remodeling factor (NURF), a member of the ISWI chromatin-remodeling complex."

Establishes BPTF's identity as the largest NURF subunit within the ISWI family.

PMID:16728976 SUPPORT In Vitro

"Here we show that a plant homeodomain (PHD) finger of nucleosome remodelling factor (NURF), an ISWI-containing ATP-dependent chromatin-remodelling complex, mediates a direct preferential association with H3K4me3 tails."

Defines the molecular reader function of the BPTF PHD finger that is lost when BPTF dosage falls.

PMID:16728976 SUPPORT In Vitro

"Depletion of H3K4me3 causes partial release of the NURF subunit, BPTF (bromodomain and PHD finger transcription factor), from chromatin and defective recruitment of the associated ATPase, SNF2L (also known as ISWI and SMARCA1), to the HOXC8 promoter."

Demonstrates the mechanistic coupling between BPTF chromatin engagement and delivery of the SNF2L remodeling ATPase to a developmental promoter.

+ 2 more references

Dysregulated Developmental Gene Transcription

Mechanism confidence: Provisional

Bptf loss alters developmental gene expression in experimental systems. In conditional-null cortex, transcriptomic changes include neuronal fate regulators and stress-response pathways. MYC-binding-site enrichment is computational and does not demonstrate BPTF/MYC occupancy or a causal interaction in patient neurons. Postnatal bulk expression differences also reflect changed cell populations, including microglia. Embryonic stem-cell experiments additionally show context-dependent activation and repression of developmental genes and impaired Smad-responsive transcription despite preserved Smad2 phosphorylation. These findings are model-specific, not a demonstrated universal failure of upstream TGF-beta signaling.

regulation of transcription by RNA polymerase II GO:0006357 ⚠ ABNORMAL

Experimental models

Bptf-null mouse embryonic stem cells and rescued embryoid bodies OTHER Directly measures Bptf-dependent transcription during differentiation and ligand stimulation.

P19 Bptf-knockdown Smad-response reporter model CELL LINE Tests a specific transcriptional consequence of Bptf depletion.

Downstream

Delayed Neural Progenitor Cell-Cycle Exit

Increased Neuronal Apoptosis

Impaired Cortical Neuron Fate Specification

Disrupted Craniofacial and Limb Patterning

Somatic Growth Impairment

Show evidence (6 references)

PMID:16728976 SUPPORT Model Organism

"Loss of BPTF in Xenopus embryos mimics WDR5 loss-of-function phenotypes, and compromises spatial control of Hox gene expression."

Directly demonstrates that BPTF loss dysregulates spatial developmental gene expression in a vertebrate embryo.

PMID:18974875 SUPPORT In Vitro

"Microarray analysis at early stages of differentiation has identified Bptf-dependent gene targets including homeobox transcriptions factors and genes essential for the development of ectoderm, mesoderm, and both definitive and visceral endoderm."

Microarray profiling during embryonic stem-cell differentiation identifies Bptf-dependent developmental genes; this is a cell-culture result.

PMID:35604347 SUPPORT Model Organism

"RNAseq and pathway analysis identified altered expression of fate-determining transcription factors and the biological pathways involved in neural development, apoptotic signaling and amino acid biosynthesis."

In the disease-specific forebrain Bptf knockout, the transcriptional consequence is misexpression of fate-determining transcription factors and neural-development/apoptosis pathways.

+ 3 more references

Delayed Neural Progenitor Cell-Cycle Exit

Mechanism confidence: Provisional

In forebrain-conditional Bptf-null mice, fewer EdU-labeled cells exited the cell cycle over 24 hours. A prolonged cycle was inferred from this assay, rather than directly timed. Radial glial abundance, S-phase fractions and mitotic-marker counts were largely unchanged, while intermediate progenitor abundance was modestly reduced. These complete-loss mouse findings have not been demonstrated in patient neural progenitors.

cortical neural progenitor cell CL:0011020

cell cycle GO:0007049 ⚠ ABNORMAL

Animal models

Bptf forebrain-conditional knockout mouse Mus musculus recapitulates Measures this candidate mechanism in a complete forebrain conditional knockout.

Downstream

Cortical Hypoplasia Altered progenitor differentiation may reduce neuronal output in the conditional-null mouse. The study does not show a general cell-cycle arrest.

Show evidence (1 reference)

url:https://pmc.ncbi.nlm.nih.gov/articles/PMC9558838/ SUPPORT Model Organism

"Taken together, the cortical progenitor cells of the ... cKO mice show no blocks in the cell cycle with similar cell proportions in the S- and M-phase to the control samples. However, fewer cells exited the cell cycle in a 24-h period suggesting that cell cycle length was prolonged, which could..."

Separates the measured cell-cycle exit fraction from the inferred cycle length and preserves negative proliferation findings.

Increased Neuronal Apoptosis

Mechanism confidence: Provisional

Forebrain Bptf conditional-null mice show increased cleaved-caspase-3 staining chiefly in the intermediate zone and cortical plate, with ventricular-zone levels largely unchanged at E15.5. The spatial pattern implicates newly postmitotic neurons undergoing differentiation or migration, rather than proving generalized progenitor apoptosis. Increased phagocytic microglia accompany postnatal cell death. This is a model-derived candidate mechanism for human disease.

differentiating cortical neuron CL:0000540

apoptotic process GO:0006915 ↑ INCREASED

Animal models

Bptf forebrain-conditional knockout mouse Mus musculus recapitulates Measures this candidate mechanism in a complete forebrain conditional knockout.

Downstream

Cortical Hypoplasia

Show evidence (2 references)

url:https://pmc.ncbi.nlm.nih.gov/articles/PMC9558838/ SUPPORT Model Organism

"We conclude from this data that a high incidence of cell death is a major contributor to the reduction in cortical size and that this occurs as the neurons become postmitotic, initiate their terminal differentiation program, and migrate toward their final laminar position."

Localizes the major cell-death contribution to differentiating neurons in the conditional-null model.

PMID:28942966 SUPPORT Model Organism

"showed a significant increase in cell death in F0 mutants compared to controls"

Independent, cross-species (zebrafish) confirmation that bptf loss increases apoptosis during neurodevelopment.

Impaired Cortical Neuron Fate Specification

Mechanism confidence: Provisional

Complete forebrain Bptf loss changes layer-specific neuronal marker expression and distribution. Ctip2-high layer V cells are reduced, whereas Ctip2-low cells increase in upper layers; total Ctip2 protein and transcript levels are not markedly reduced. Birth-dating does not show fewer EdU/Ctip2-colabeled cells, supporting impaired regulation and maturation rather than simply absent production of this neuronal class. These findings do not establish cortical mislamination in human heterozygous disease.

cortical projection neuron CL:0000540

cerebral cortex neuron differentiation GO:0021895 ↓ DECREASED

Animal models

Bptf forebrain-conditional knockout mouse Mus musculus recapitulates Measures this candidate mechanism in a complete forebrain conditional knockout.

Downstream

Neurodevelopmental Impairment Altered cortical neuronal identity may affect circuit function, but cognition and seizure physiology were not characterized in this mouse study.

Show evidence (2 references)

url:https://pmc.ncbi.nlm.nih.gov/articles/PMC9558838/ SUPPORT Model Organism

"Immunoblots suggested the overall levels of Ctip2 were not markedly different than in the control extracts"

Preserves the negative bulk-protein result despite altered layer-specific Ctip2 staining.

url:https://pmc.ncbi.nlm.nih.gov/articles/PMC9558838/ SUPPORT Model Organism

"suggesting that these cells are specified but have impaired Ctip2 regulation that alters lamination and terminal expression levels."

Interpretation of the birth-dating experiment; the neuron class is not simply absent at birth.

Cortical Hypoplasia

Mechanism confidence: Provisional

Forebrain-conditional Bptf-null mice have reduced cortical size from birth. Gross anatomy did not progressively worsen with age. This provides a developmental model for reduced brain growth, but most imaged individuals in the human expansion cohort had normal MRI and the remaining changes were heterogeneous. Mouse cortical hypoplasia cannot be equated with every human MRI abnormality or with a demonstrated cause of human epilepsy.

cortical projection neuron CL:0000540

cerebral cortex development GO:0021987 ⚠ ABNORMAL

cerebral cortex UBERON:0000956

Animal models

Bptf forebrain-conditional knockout mouse Mus musculus recapitulates Reduced cortical size is directly observed in the conditional-null model.

Downstream

Reduced Brain Growth The conditional-null cortical phenotype provides a candidate route to human microcephaly; the human cellular substrate and dosage relationship remain unresolved.

Show evidence (2 references)

PMID:35604347 SUPPORT Model Organism

"The Bptf cKO mice were born in normal Mendelian ratios, survived to adulthood but were smaller in size with severe cortical hypoplasia."

Establishes cortical hypoplasia with reduced body size as the tissue-level phenotype of forebrain Bptf loss.

url:https://pmc.ncbi.nlm.nih.gov/articles/PMC9558838/ SUPPORT Model Organism

"The gross morphology of the hypoplastic forebrain remained identical to the P12 mice as the mice aged"

Supports a developmental, grossly nonprogressive anatomical phenotype in the model.

Disrupted Craniofacial and Limb Patterning

Mechanism confidence: Provisional

Zebrafish bptf disruption increases the ceratohyal cartilage angle, supporting a role in craniofacial development. The specific cellular lineage and molecular route to human facial or distal limb findings have not been demonstrated. A shared developmental-patterning disturbance is proposed, rather than an established migratory neural-crest defect or a measured human HOX-expression mechanism.

embryonic skeletal system morphogenesis GO:0048704 ⚠ ABNORMAL embryonic limb morphogenesis GO:0030326 ⚠ ABNORMAL

Animal models

bptf CRISPR F0 crispant zebrafish Danio rerio partially recapitulates Increased ceratohyal angle is an established quantitative readout of disrupted craniofacial patterning, and is the direct experimental support for the craniofacial arm of this node.

Downstream

Dysmorphic Facial Features A candidate developmental connection based on co-occurring human findings and experimental craniofacial abnormalities; the human causal route is unproven.

Distal Limb Anomalies A candidate developmental connection based on co-occurring human findings and experimental craniofacial abnormalities; the human causal route is unproven.

Show evidence (3 references)

PMID:28942966 SUPPORT Model Organism

"we observed a substantial increase of the ceratohyal angle of the craniofacial skeleton in bptf F0 mutants, indicating abnormal craniofacial patterning"

Experimental demonstration that bptf loss disrupts craniofacial patterning, the model-organism correlate of the human dysmorphic facies.

PMID:16728976 SUPPORT In Vitro

"NURF-mediated ATP-dependent chromatin remodelling is directly coupled to H3K4 trimethylation to maintain Hox gene expression patterns during development"

Supplies the HOX-patterning link that makes limb and craniofacial patterning a plausible consequence of BPTF loss; indirect with respect to the human limb findings, whose specific molecular route remains unproven.

PMID:33522091 SUPPORT Human Clinical

"The mechanism for these abnormalities is less clear, though it is presumed that they are also derived from abnormal signaling during embryogenesis similar to the distal limb defects commonly described in these patients."

The disease literature itself states the developmental-patterning inference is presumptive, which is why this node is PROVISIONAL.

Reduced Brain Growth

Mechanism confidence: Provisional

Microcephaly in BPTF-related disease can be congenital or emerge after birth. Reduced larval head size after zebrafish bptf disruption and cortical hypoplasia in conditional-null mice support a developmental contribution, but the exact cellular route in human heterozygous disease is unresolved. Microcephaly and neurodevelopmental impairment may share upstream causes; reduced head size does not itself establish the cause of cognitive impairment.

Animal models

bptf CRISPR F0 crispant zebrafish Danio rerio partially recapitulates Reduced head size in bptf F0 larvae is the cross-species correlate of the human microcephaly.

Downstream

Microcephaly Reduced brain growth provides a candidate basis for small head circumference across congenital and postnatal presentations; the precise human cellular mechanism remains unresolved.

Postnatal Microcephaly Reduced postnatal brain growth is a plausible basis for secondary microcephaly documented in the founding cohort. This timing-specific phenotype is a subset of the general microcephaly finding.

Show evidence (2 references)

PMID:28942966 SUPPORT Human Clinical

"who manifest variable degrees of developmental delay/intellectual disability (10/10), speech delay (10/10), postnatal microcephaly (7/9), and dysmorphic features (9/10)"

Establishes the postnatal (rather than congenital) timing of the microcephaly in the founding cohort.

PMID:28942966 SUPPORT Model Organism

"Using CRISPR-Cas9 genome editing of bptf in zebrafish to induce a loss of gene function, we observed a significant reduction in head size of F0 mutants compared to control larvae."

Model-organism recapitulation of reduced head size on bptf loss.

Somatic Growth Impairment

Mechanism confidence: Provisional

Short stature, low weight and feeding difficulty occur variably in human BPTF-related disease. Growth hormone deficiency was documented in two treated boys, but is not established as the explanation for all growth impairment. The connection between chromatin dysregulation and somatic growth remains uncertain and is separate from the brain-growth mechanism.

Downstream

Short Stature

Poor Weight Gain and Malnutrition Feeding difficulty and other factors may contribute; low weight alone does not establish growth velocity or a single causal pathway.

Decreased Body Weight Somatic growth impairment can present as low weight for age. The cohort measurements establish this association without identifying the relative contributions of feeding or endocrine factors.

Show evidence (1 reference)

PMID:33522091 SUPPORT Human Clinical

"At the time of their most recent clinical assessment, 5/20 (25%) individuals exhibited short stature for age and 10/19 (53%) individuals had decreased weight for age"

Quantifies the somatic growth restriction that accompanies the microcephaly.

Neurodevelopmental Impairment

Mechanism confidence: Established

Human BPTF-related disease includes developmental delay, intellectual disability, speech/language delay, motor delay and hypotonia with variable expressivity. Some individuals function independently as adults. Developmental delay commonly precedes seizures, but this does not prove a specific cortical lesion or exclude additional developmental effects from epilepsy.

Downstream

Global Developmental Delay The impairment presents first as delayed attainment of milestones across all developmental domains.

Intellectual Disability Intellectual disability occurs in some affected individuals; global developmental delay does not invariably imply later intellectual disability.

Delayed Speech and Language Development Speech and language are disproportionately affected relative to other domains, making this the most consistent single manifestation.

Motor Delay Gross and fine motor milestones are delayed alongside the cognitive and language domains.

Hypotonia Hypotonia accompanies the neurodevelopmental phenotype; its specific causal route is unresolved.

Show evidence (2 references)

PMID:33522091 SUPPORT Human Clinical

"Common features included DD and/or ID (23/26, 88%), speech delay (22/26, 85%), head circumference less than the third percentile for age (11/26, 42%), motor delay (18/26, 69%), hypotonia (10/26, 38%), and dysmorphic features (20/26, 77%)."

Quantifies the organism-level clinical output across the largest single-study cohort.

PMID:38936258 SUPPORT Human Clinical

"developmental delay preceding seizure onset"

Reports temporal ordering of developmental delay and seizures without establishing a cortical lesion or a causal relationship.

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Pathograph

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Phenotypes

44

Digestive 3

Feeding Difficulties HP:0011968

Frequency omitted: PMID:33522091 reports poor feeding qualitatively as an increased-frequency finding without a numerator/denominator.

Show evidence (1 reference)

PMID:33522091 SUPPORT Human Clinical

"In addition to DDs, microcephaly, and distal limb defects, our cohort exhibited an increased frequency of ophthalmologic abnormalities, poor weight gain/poor feeding, and cutaneous syndactyly of the toes."

Names poor feeding as an expanded feature of NEDDFL.

Cyclical Vomiting Syndrome Episodic vomiting HP:0002572

Temporal: RECURRENT

Three of 15 individuals met full ICHD-3 CVS criteria, and four additional individuals met at least three criteria. The study recruited families with or without gastrointestinal symptoms. The 20% CVS proportion is from this small questionnaire cohort and is not the frequency of all episodic vomiting.

Show evidence (2 references)

PMID:40614698 SUPPORT Human Clinical

"We enrolled 15 individuals with likely pathogenic/pathogenic BPTF variants (median age: 8.8 years). Three individuals (20%) were diagnosed with CVS, and an additional four individuals (26.7%) met at least three of the ICHD-3 criteria for CVS."

Distinguishes the three confirmed CVS cases from four additional individuals with recurrent vomiting meeting partial criteria.

PMID:40614698 SUPPORT Human Clinical

"This study broadens the syndromic phenotype associated with BPTF haploinsufficiency, highlighting CVS as a core feature."

The authors propose CVS as part of the syndrome; the small observational series establishes an association rather than proving causality for each episode.

Constipation HP:0002019

Show evidence (1 reference)

PMID:33522091 SUPPORT Human Clinical

"History of feeding difficulties with oral aversion, GERD, poor weight gain and constipation. Diagnosed with global developmental delay"

Patient 1 has constipation; Table 2 also documents it in patients 7 and 19.

Endocrine 1

Growth Hormone Deficiency on Stimulation Testing Decreased response to growth hormone stimulation test HP:0000824

Show evidence (2 references)

PMID:36153657 SUPPORT Human Clinical

"He was diagnosed with growth hormone deficiency (GHD), with a growth hormone (GH) peak of 4.39 ng/ml in both arginine and levodopa stimulation tests."

Directly supports decreased response to growth hormone stimulation testing in patient 1.

PMID:36153657 SUPPORT Human Clinical

"He was also diagnosed with GHD, with a GH peak of 6.36 ng/ml in both arginine and levodopa stimulation tests."

Directly supports reduced stimulated GH in patient 2.

Eye 5

Exotropia HP:0000577

The 2021 report described 13 individuals with ophthalmologic findings overall, including six with exotropia, two with other strabismus and three with confirmed myopia. These categories may overlap and do not supply a uniformly examined denominator for each specific phenotype.

Show evidence (1 reference)

PMID:33522091 SUPPORT Human Clinical

"Interestingly, 13 individuals demonstrated mild ophthalmologic abnormalities. These included the finding of exotropia in six individuals, strabismus in two individuals, and confirmed myopia in three individuals."

Documents exotropia as the most common specific ophthalmologic finding.

Myopia HP:0000545

Frequency omitted for the same denominator ambiguity as exotropia.

Show evidence (1 reference)

PMID:33522091 SUPPORT Human Clinical

"Interestingly, 13 individuals demonstrated mild ophthalmologic abnormalities. These included the finding of exotropia in six individuals, strabismus in two individuals, and confirmed myopia in three individuals."

Documents confirmed myopia in the cohort.

Hypermetropia HP:0000540

Show evidence (1 reference)

PMID:33522091 SUPPORT Human Clinical

"First toe bilaterally is slightly laterally deviated and a little bit broad | Stable hyperopia and alternating exotropia, wears glasses"

The eye-anomaly cell for patient 21 documents hyperopia and glasses; hypermetropia is also listed for patient 26.

Astigmatism HP:0000483

Show evidence (1 reference)

PMID:33522091 SUPPORT Human Clinical

"Epicanthal folds, prominent pointed helices with prominent antihelices; prominent nasal root, mild bulbous nasal tip | Astigmatism, myopia, right eye exotropia"

Patient 8 has astigmatism and myopia; patient 1 also has this combination.

Strabismus HP:0000486

Show evidence (1 reference)

PMID:33522091 SUPPORT Human Clinical

"Lateral flaring of eyebrows, narrow palpebral fissures, prominent ears and cheekbones, small mouth, micrognathia | Transient strabismus when tired"

Patient 17 illustrates strabismus beyond the separately recorded exotropia phenotype.

Head and Neck 13

Postnatal Microcephaly Secondary microcephaly HP:0005484

Onset: INFANTILE

The 2021 overall microcephaly counts include individuals small-headed at birth and therefore cannot supply a frequency for secondary microcephaly.

Show evidence (2 references)

PMID:28942966 SUPPORT Human Clinical

"who manifest variable degrees of developmental delay/intellectual disability (10/10), speech delay (10/10), postnatal microcephaly (7/9), and dysmorphic features (9/10)"

Names the microcephaly as postnatal and reports it in 7/9 assessed individuals in the founding cohort.

PMID:33522091 SUPPORT Human Clinical

"12/20 (60%) individuals demonstrated a head circumference less than the third percentile for age"

Quantifies microcephaly at last clinical assessment in the expansion cohort.

Dysmorphic Facial Features VERY_FREQUENT Abnormal facial shape HP:0001999

Severity: MILD

Frequency band from PMID:33522091, in which mild dysmorphic features were present in all 20 individuals with available dysmorphology assessment (20/20 -> VERY_FREQUENT); the same paper reports 20/26 (77%) over the whole cohort including individuals not assessed, and the founding cohort reported 9/10.

Show evidence (2 references)

PMID:33522091 SUPPORT Human Clinical

"mild dysmorphic features were identified in all available subjects (20/20 individuals)"

Supplies the 20/20 denominator for the VERY_FREQUENT band and establishes that the dysmorphism is mild.

PMID:28942966 SUPPORT Human Clinical

"who manifest variable degrees of developmental delay/intellectual disability (10/10), speech delay (10/10), postnatal microcephaly (7/9), and dysmorphic features (9/10)"

Dysmorphic features in 9/10 of the founding cohort.

Bulbous Nasal Tip Bulbous nose HP:0000414

The 2021 report counted nasal abnormalities collectively in 9/20 assessed individuals. This includes prominent nasal tip, bulbous nasal tip and prominent nasal bridge and does not establish the frequency of this individual feature.

Show evidence (1 reference)

PMID:33522091 SUPPORT Human Clinical

"Commonly identified features included a number of nasal abnormalities (prominent nasal tip, bulbous nasal tip, and prominent nasal bridge) in 9/20 (45%) individuals"

Names bulbous nasal tip among the recurrent nasal features and supplies the 45% group denominator.

Prominent Nasal Bridge HP:0000426

The 2021 report counted nasal abnormalities collectively in 9/20 assessed individuals. This includes prominent nasal tip, bulbous nasal tip and prominent nasal bridge and does not establish the frequency of this individual feature.

Show evidence (1 reference)

PMID:33522091 SUPPORT Human Clinical

"Commonly identified features included a number of nasal abnormalities (prominent nasal tip, bulbous nasal tip, and prominent nasal bridge) in 9/20 (45%) individuals"

Names prominent nasal bridge among the recurrent nasal features.

Pointed Chin HP:0000307

Frequency omitted: PMID:33522091 documents pointed chin only in the photograph legend, without a numerator/denominator, so no band can be derived.

Show evidence (1 reference)

PMID:33522091 SUPPORT Human Clinical

"bulbous nasal tip (a, d, h, k, m, n), and pointed chin (a, c, d, e, f, i, k, m, n)"

Clinical photograph annotation documenting pointed chin across multiple individuals.

Micrognathia HP:0000347

Show evidence (1 reference)

PMID:33522091 SUPPORT Human Clinical

"Metopic ridge, brachycephaly, mild micrognathia, synophrys, apparently long tongue, cutis marmorata; square finger tips, moderate soft tissue syndactyly of toes 2 and 3, broad great toes and thumbs, wide sandal gap deformities"

Table 2 explicitly identifies mild micrognathia in patient 7.

High Palate HP:0000218

Show evidence (1 reference)

PMID:33522091 SUPPORT Human Clinical

"Right microtia with over‐folded helix, epicanthal folds, upslanting palpebral fissures, high palate, micrognathia, bulbous nasal tip; small body habitus (including hands and feet), fine hair on the back, one hyperpigmented and one hypopigmented macule"

Table 2 records a high palate in patient 12; it is also reported in patients 6, 11 and 22.

Thin Upper Lip Vermilion HP:0000219

Show evidence (1 reference)

PMID:33522091 SUPPORT Human Clinical

"Mild facial dysmorphism—short palpebral fissures, thin upper lip lateral flaring of eyebrows | No | None | Normal brain MRI | EEG abnormalities, focal temporoparietal left, but no clinical seizures"

Table 2 records a thin upper lip in patient 24, with similar findings in other individuals.

Epicanthus HP:0000286

Show evidence (1 reference)

PMID:33522091 SUPPORT Human Clinical

"Bilateral epicanthal folds, slightly short palpebral fissures, tubular nose, flat cheekbones, fetal fingertip pads, mild 2–3 syndactyly of the feet, borderline low tone"

Table 2 explicitly documents bilateral epicanthal folds in patient 1.

Upslanted Palpebral Fissures HP:0000582

Show evidence (1 reference)

PMID:33522091 SUPPORT Human Clinical

"Right microtia with over‐folded helix, epicanthal folds, upslanting palpebral fissures, high palate, micrognathia, bulbous nasal tip; small body habitus (including hands and feet), fine hair on the back, one hyperpigmented and one hypopigmented macule"

Table 2 records upslanting palpebral fissures in patient 12; similar observations occur in patients 19, 21 and 25.

Short Palpebral Fissures HP:0012745

Show evidence (1 reference)

PMID:33522091 SUPPORT Human Clinical

"Bilateral epicanthal folds, slightly short palpebral fissures, tubular nose, flat cheekbones, fetal fingertip pads, mild 2–3 syndactyly of the feet, borderline low tone"

Patient 1 explicitly has slightly short palpebral fissures.

Broad Lateral Eyebrows HP:0007933

Show evidence (1 reference)

PMID:33522091 SUPPORT Human Clinical

"Mild facial dysmorphism—short palpebral fissures, thin upper lip lateral flaring of eyebrows | No | None | Normal brain MRI | EEG abnormalities, focal temporoparietal left, but no clinical seizures"

The lateral eyebrow flaring in patient 24 maps to broad lateral eyebrow.

Microcephaly HP:0000252

Show evidence (1 reference)

PMID:33522091 SUPPORT Human Clinical

"Though head circumferences were not provided for every individual, consistent with previous observations (Stankiewicz et al., 2017), 12/20 (60%) individuals demonstrated a head circumference less than the third percentile for age."

Supports microcephaly without assuming postnatal onset for every individual.

Integument 1

Cafe-au-Lait Macules Cafe-au-lait spot HP:0000957

Show evidence (1 reference)

PMID:33522091 SUPPORT Human Clinical

"Low set ears, slightly upslanting palpebral fissures, epicanthal folds, 3 small irregular café au lait macules, unilateral single palmar crease"

Table 2 records cafe-au-lait macules in patient 25; similar observations occur in patients 5 and 26.

Limbs 5

Distal Limb Anomalies Abnormal digit morphology HP:0011297

Skeletal abnormalities occurred in 13/26 individuals in the 2021 cohort, but that count also includes scoliosis, kyphosis and delayed bone age. It cannot estimate distal limb or digit abnormalities specifically.

Show evidence (3 references)

PMID:33522091 SUPPORT Human Clinical

"we also identified the presence of skeletal abnormalities in 50% (13/26) of individuals"

Describes the broader skeletal group, including axial abnormalities; the 13/26 count is not a digit-specific frequency.

PMID:33522091 SUPPORT Human Clinical

"In addition to DDs, microcephaly, and distal limb defects, our cohort exhibited an increased frequency of ophthalmologic abnormalities, poor weight gain/poor feeding, and cutaneous syndactyly of the toes."

Names cutaneous syndactyly of the toes as a recurrent distal limb finding.

PMID:40415676 SUPPORT Human Clinical

"Additionally, all four of our cases in this study had distal limb abnormalities such as syndactyly and clinodactyly that accompany severe intellectual disability."

Describes syndactyly and clinodactyly in four individuals, but three carry missense VUS and cannot be used as independent genetically confirmed cases for a frequency estimate.

Sandal Gap HP:0001852

Frequency omitted: PMID:33522091 reports a raw count of five individuals within the subgroup of 13 with skeletal abnormalities, without a whole-cohort denominator.

Show evidence (1 reference)

PMID:33522091 SUPPORT Human Clinical

"Note the presence of fifth finger clinodactyly (d), sandal gap deformity (i, k) and cutaneous syndactyly (j, k)"

Clinical photograph annotation documenting sandal gap in the cohort.

Fifth-Finger Clinodactyly Clinodactyly of the 5th finger HP:0004209

Frequency omitted: documented in PMID:33522091 only as a photograph annotation without a denominator, and in PMID:40415676 in all four cases of a small ascertained series.

Show evidence (1 reference)

PMID:33522091 SUPPORT Human Clinical

"Note the presence of fifth finger clinodactyly (d), sandal gap deformity (i, k) and cutaneous syndactyly (j, k)"

Clinical photograph annotation documenting fifth-finger clinodactyly.

Cutaneous Toe Syndactyly Cutaneous syndactyly of toes HP:0010621

Show evidence (1 reference)

PMID:33522091 SUPPORT Human Clinical

"Metopic ridge, brachycephaly, mild micrognathia, synophrys, apparently long tongue, cutis marmorata; square finger tips, moderate soft tissue syndactyly of toes 2 and 3, broad great toes and thumbs, wide sandal gap deformities"

Table 2 documents soft-tissue toe syndactyly in patient 7; the separate familial explanation for patient 18 prevents assuming that every syndactyly observation is caused by BPTF.

Broad Great Toes Broad hallux HP:0010055

Show evidence (1 reference)

PMID:33522091 SUPPORT Human Clinical

"Metopic ridge, brachycephaly, mild micrognathia, synophrys, apparently long tongue, cutis marmorata; square finger tips, moderate soft tissue syndactyly of toes 2 and 3, broad great toes and thumbs, wide sandal gap deformities"

Patient 7 has broad great toes, also described in several other Table 2 cases.

Musculoskeletal 4

Hypotonia FREQUENT HP:0001252

Frequency band from PMID:33522091 (hypotonia 10/26, 38% -> FREQUENT); the pooled table in PMID:36153657 reports 15/38 (39%), concordant.

Show evidence (1 reference)

PMID:33522091 SUPPORT Human Clinical

"Common features included DD and/or ID (23/26, 88%), speech delay (22/26, 85%), head circumference less than the third percentile for age (11/26, 42%), motor delay (18/26, 69%), hypotonia (10/26, 38%), and dysmorphic features (20/26, 77%)."

Hypotonia in 10/26 (38%), mapping to FREQUENT.

Scoliosis OCCASIONAL HP:0002650

Band derived conservatively: PMID:33522091 reports 5/13 (38.5%) of the skeletal-abnormality subgroup, which corresponds to 5/26 (19%) of the whole cohort. The whole-cohort denominator is the appropriate one for a disease-level frequency, giving OCCASIONAL (5-29%).

Show evidence (1 reference)

PMID:33522091 SUPPORT Human Clinical

"These included the presence of scoliosis in five individuals (5/13, 38.5%)"

Supplies the scoliosis count within the skeletal-abnormality subgroup of the 26-individual cohort.

Delayed Bone Age Delayed skeletal maturation HP:0002750

Frequency omitted: only two individuals, reported as a raw count within the skeletal-abnormality subgroup of PMID:33522091.

Show evidence (1 reference)

PMID:33522091 SUPPORT Human Clinical

"and delayed bone age in two individuals (2/13, 15%)"

Documents delayed skeletal maturation in the cohort.

Kyphosis HP:0002808

Show evidence (1 reference)

PMID:33522091 SUPPORT Human Clinical

"Thoracic kyphosis, sandal gap both feet, 2–3 syndactyly of both feet, broad great toes, long slender fingers"

Table 2 records thoracic kyphosis in patient 20; patient 5 also has a mild thoracic kyphotic deformity.

Nervous System 9

Global Developmental Delay HP:0001263

The 2021 cohort reported developmental delay and/or intellectual disability jointly in 23/26 individuals. This composite does not provide a separate global-developmental-delay frequency. The 2017 cohort also reported the two findings jointly.

Show evidence (2 references)

PMID:33522091 SUPPORT Human Clinical

"Common features included DD and/or ID (23/26, 88%), speech delay (22/26, 85%), head circumference less than the third percentile for age (11/26, 42%), motor delay (18/26, 69%), hypotonia (10/26, 38%), and dysmorphic features (20/26, 77%)."

Supports the combined developmental-delay/intellectual-disability phenotype; it does not distinguish the frequency of each component.

PMID:28942966 SUPPORT Human Clinical

"who manifest variable degrees of developmental delay/intellectual disability (10/10), speech delay (10/10), postnatal microcephaly (7/9), and dysmorphic features (9/10)"

Founding cohort: developmental delay/intellectual disability in all ten individuals.

Intellectual Disability HP:0001249

The 23/26 composite developmental delay and/or intellectual disability count does not estimate intellectual disability separately.

Show evidence (2 references)

PMID:33522091 SUPPORT Human Clinical

"Common features included DD and/or ID (23/26, 88%), speech delay (22/26, 85%), head circumference less than the third percentile for age (11/26, 42%), motor delay (18/26, 69%), hypotonia (10/26, 38%), and dysmorphic features (20/26, 77%)."

Provides the composite DD/ID fraction.

PMID:40415676 SUPPORT Human Clinical

"We suggest that distal limb abnormalities associated with the BPTF gene may accompany a more severe diagnosis of intellectual disability."

An exploratory severity hypothesis from four individuals, three with missense VUS; it is not an established prognostic association.

Delayed Speech and Language Development VERY_FREQUENT HP:0000750

Frequency band from PMID:33522091 (speech delay 22/26, 85% -> VERY_FREQUENT); the founding cohort reported 10/10 and the pooled 38-case table in PMID:36153657 gives 33/38 (87%).

Show evidence (2 references)

PMID:28942966 SUPPORT Human Clinical

"who manifest variable degrees of developmental delay/intellectual disability (10/10), speech delay (10/10), postnatal microcephaly (7/9), and dysmorphic features (9/10)"

Speech delay in 10/10 of the founding cohort.

PMID:33522091 SUPPORT Human Clinical

"Common features included DD and/or ID (23/26, 88%), speech delay (22/26, 85%), head circumference less than the third percentile for age (11/26, 42%), motor delay (18/26, 69%), hypotonia (10/26, 38%), and dysmorphic features (20/26, 77%)."

Supplies the 85% denominator for the VERY_FREQUENT band.

Motor Delay FREQUENT HP:0001270

Frequency band from the original 2021 cohort: motor delay in 18/26 (69%), corresponding to FREQUENT. The later pooled table prints 26/28 as 68%, an arithmetic inconsistency, and is not used for this frequency.

Show evidence (1 reference)

PMID:33522091 SUPPORT Human Clinical

"Common features included DD and/or ID (23/26, 88%), speech delay (22/26, 85%), head circumference less than the third percentile for age (11/26, 42%), motor delay (18/26, 69%), hypotonia (10/26, 38%), and dysmorphic features (20/26, 77%)."

Motor delay in 18/26 (69%) of the expansion cohort, mapping to FREQUENT.

Epilepsy OCCASIONAL Seizure HP:0001250

Onset: CHILDHOOD

The 2024 authors report epilepsy in 19% of known subjects; this is a literature-based proportion, distinct from the selected eleven-person electroclinical series. The 2021 cohort includes four individuals with clinical seizures and two with EEG abnormalities only, rather than six confirmed epilepsy cases.

Show evidence (2 references)

PMID:38936258 SUPPORT Human Clinical

"Early-childhood-onset epilepsy occurs in 19% of subjects, all presenting with a well-organized EEG background associated with generalized interictal epileptiform abnormalities in half of these cases. Drug resistance is rare."

Supplies both the 19% frequency underpinning the OCCASIONAL band and the electroclinical characterization.

PMID:33522091 SUPPORT Human Clinical

"Here, however, we identified six individuals with a history of clinical seizures and/or abnormal electroencephalograms (manuscript in preparation)."

Independent cohort confirming seizures as part of the NEDDFL spectrum and noting they were previously unreported.

EEG Abnormality HP:0002353

Frequency omitted: the denominator (11 individuals) is an epilepsy-ascertained series, not an unselected NEDDFL cohort, so a population band cannot be derived.

Show evidence (1 reference)

PMID:38936258 SUPPORT Human Clinical

"Eight individuals had epilepsy, one had a single unprovoked seizure, and two showed IEDs only."

Documents isolated interictal epileptiform discharges as a distinct electrographic finding.

Structural Brain Abnormality FREQUENT Abnormal brain morphology HP:0012443

Severity: MILD

Coarse binding: source unspecified

The FREQUENT band refers to five of thirteen imaged individuals in the 2021 cohort, not a population prevalence. The broad binding retains the unspecified structural-abnormality category used in the quoted cohort summary; individual MRI findings are heterogeneous. The later pooled table is not used to infer a syndrome-wide imaging frequency.

Show evidence (1 reference)

PMID:33522091 SUPPORT Human Clinical

"Magnetic resonance imaging (MRI) studies were obtained for 13/26 patients and were found to be normal in 8/13 cases. The remaining five studies demonstrated mild structural abnormalities only"

Provides the 5/13 abnormal MRI fraction and characterizes changes as mild within this cohort, without establishing a uniform human cortical lesion.

Autism HP:0000717

Show evidence (1 reference)

PMID:33522091 SUPPORT Human Clinical

"ID | Variant | Sex | Age | DD/ID | Speech delay | Motor delay | Hypotonia | Autism | ADHD | Dysmorphic features ... Patient 3 | c.255delC (p.Ser86Alafs*151) | F | 22 years | + | + | + | + | + | + | Prominent nasal ridge, thin upper lip"

Table 2 marks autism present in patient 3; patients 14 and 17 are also marked positive. The heading is retained to identify the table columns.

Attention Deficit Hyperactivity Disorder HP:0007018

Show evidence (1 reference)

PMID:33522091 SUPPORT Human Clinical

"ID | Variant | Sex | Age | DD/ID | Speech delay | Motor delay | Hypotonia | Autism | ADHD | Dysmorphic features ... Patient 3 | c.255delC (p.Ser86Alafs*151) | F | 22 years | + | + | + | + | + | + | Prominent nasal ridge, thin upper lip"

Table 2 marks ADHD present in patient 3; patients 7 and 17 are also marked positive. The heading identifies the otherwise ambiguous plus signs.

Growth 3

Short Stature FREQUENT HP:0004322

Frequency band from PMID:36153657, which states in its abstract that about 35% of patients have short stature -> FREQUENT. PMID:33522091 independently reports 5/20 (25%) at last assessment, which would map to OCCASIONAL; the larger pooled denominator behind the 35% figure is preferred, and the discrepancy is recorded here rather than hidden.

Show evidence (2 references)

PMID:36153657 SUPPORT Human Clinical

"About 35% of the patients had short stature, but there had no reports published on the treatment."

Explicit 35% short-stature frequency supporting the FREQUENT band.

PMID:33522091 SUPPORT Human Clinical

"At the time of their most recent clinical assessment, 5/20 (25%) individuals exhibited short stature for age and 10/19 (53%) individuals had decreased weight for age"

The independent cohort estimate of 25% supports the short-stature association but falls in a different frequency band from the later pooled estimate of 35%.

Poor Weight Gain and Malnutrition Failure to thrive HP:0001508

The expansion cohort reported weight below the third percentile in 10/19 assessed individuals. A single low-weight measurement is not equivalent to poor weight gain or failure to thrive, so this proportion is not used as a frequency for this entry.

Show evidence (1 reference)

PMID:33522091 SUPPORT Human Clinical

"At the time of their most recent clinical assessment, 5/20 (25%) individuals exhibited short stature for age and 10/19 (53%) individuals had decreased weight for age"

Documents low weight for age; this supports the growth phenotype but does not by itself establish the rate of weight gain.

Decreased Body Weight HP:0004325

Show evidence (1 reference)

PMID:33522091 SUPPORT Human Clinical

"At the time of their most recent clinical assessment, 5/20 (25%) individuals exhibited short stature for age and 10/19 (53%) individuals had decreased weight for age (based on measurements less than the third percentiles for height and weight respectively)."

Provides the measured low-weight fraction independently of diagnoses of poor weight gain or malnutrition.

🧬

Genetic Associations

1

BPTF (Heterozygous pathogenic variants disrupting BPTF cause an autosomal dominant neurodevelopmental disorder, with haploinsufficiency as the principal mechanism. Reported allele classes include frameshift, nonsense, splice-site, exon or whole-gene deletions, gene-disrupting rearrangements, in-frame deletions and missense substitutions. Clinical severity cannot be reliably predicted from allele class alone. The two missense variants in the 2025 four-person report were classified as variants of uncertain significance, so that series does not establish their pathogenicity or a missense-specific severe phenotype.)

Gene: BPTF hgnc:3581 relationship_type: CAUSATIVE variant_origin: GERMLINE

Show evidence (4 references)

PMID:28942966 SUPPORT Human Clinical

"we report eight loss-of-function and two missense variants (eight de novo and two of unknown origin) in BPTF on 17q24.2"

Establishes BPTF at 17q24.2 as the causative locus and shows the loss-of-function-dominant allelic spectrum.

PMID:33522091 SUPPORT Human Clinical

"Our analysis identified 20 novel, distinct variants in BPTF (Table 1) distributed throughout the gene (Figure 1), including 14 de novo and four inherited."

Documents variants distributed across BPTF and the reported inheritance counts; this sample does not establish the absence of recurrent alleles.

PMID:40415676 SUPPORT Human Clinical

"We detected two novel missense variants in patients presenting all phenotypic characteristics of the BPTF-related NEDDFL syndrome severely, including severe ID, distinctive facial features, and anomalies of the hands and feet."

The authors describe severe findings in missense carriers, but their full-text results classify both missense variants as VUS. These observations do not establish a genotype-severity relationship.

+ 1 more reference

🔬

Variants

5

NM_004459.6:c.1133G>A (p.Arg378Gln) Likely Pathogenic

Gene: BPTF hgnc:3581 single nucleotide variant

Reported as likely pathogenic in the 2023 growth-hormone case series. Neither parent carried the variant, but parentage was not confirmed. The source classification is retained; direct functional validation was not reported.

Show evidence (2 references)

PMID:36153657 SUPPORT Human Clinical

"In patient 1, a heterozygous c.1133G>A (p.Arg378Gln) novel missense variant was detected in BPTF (NM_004459.6). Both parents were wild‐type for this variant"

Identifies the transcript, substitution and parental result.

PMID:36153657 SUPPORT Human Clinical

"This variant is considered to be likely pathogenic based on the ACMG/AMP standards and guidelines ... This genetic abnormality is assumed de novo, but without confirmation of paternity and maternity (PM6)."

Records the authors' classification and the limit on de novo confirmation.

NM_004459.6:c.5941delC (p.Pro1981LeufsTer33) Likely Pathogenic

Gene: BPTF hgnc:3581 deletion

Frameshift reported as likely pathogenic and confirmed de novo in the second child in the 2023 series. Loss of function was predicted; no patient RNA or protein assay demonstrated the specific consequence.

Show evidence (2 references)

PMID:36153657 SUPPORT Human Clinical

"In patient 2, a heterozygous c.5941delC (p.P1981Lfs*33) novel frameshift variant was detected in BPTF (NM_004459.6). Both parents were wild‐type for this variant"

Identifies the frameshift and its source transcript.

PMID:36153657 SUPPORT Human Clinical

"As in case 1, this variant is considered to be likely pathogenic based on the ACMG/AMP standards and guidelines ... The variant is confirmed de novo in a patient with the disease and no family history (PS2)."

Preserves the source classification and confirmed de novo status.

NM_182641.4:c.2812+1G>C Pathogenic

Gene: BPTF hgnc:3581 single nucleotide variant

De novo splice-donor substitution classified as pathogenic in the 2025 report. Splicing disruption was predicted; the paper does not demonstrate a particular abnormal transcript or protein product.

Show evidence (2 references)

PMID:40415676 SUPPORT Human Clinical

"We identified a novel heterozygous non‐coding variant in the BPTF (NM_182641.4): c.2812+1G>C through WES. This splice‐site variant is likely to disrupt normal splicing of the BPTF gene, which could result in abnormal mRNA processing and produce a non‐functional or truncated protein."

Distinguishes the physical donor-site substitution from its predicted RNA consequence.

PMID:40415676 SUPPORT Human Clinical

Table 1 provides the pathogenic classification and de novo status.

NM_182641.4:c.6022G>A (p.Val2008Ile) Uncertain Significance

Gene: BPTF hgnc:3581 single nucleotide variant

Paternally inherited missense VUS in the 2025 series. The father was not clinically examined in detail; this observation does not establish pathogenicity, penetrance or a missense-specific severity relationship.

Show evidence (1 reference)

PMID:40415676 SUPPORT Human Clinical

The source table explicitly labels this variant VUS.

NM_182641.4:c.6416G>A (p.Arg2139His) Uncertain Significance

Gene: BPTF hgnc:3581 single nucleotide variant

Maternally inherited missense VUS reported in a daughter and mother. The mother had reported intellectual disability and hand findings but did not attend for detailed examination. Pathogenicity remains uncertain.

Show evidence (2 references)

PMID:40415676 SUPPORT Human Clinical

"In Case #3, WES also detected the variant NM_182641.4: c.6416G>A: p.Arg2139His in the BPTF gene. This variant was inherited from the mother."

Identifies the variant and segregation.

PMID:40415676 SUPPORT Human Clinical

"This change, p.Arg2139His, is classified as uncertain significance (PM2, PP2) in silico variant analysis databases according to the ACMG."

Preserves the explicit uncertain classification.

💊

Medical Actions

8

Supportive and Developmental Therapy

Category: Therapeutic Action: supportive care Ontology label: Supportive Care NCIT:C15747

Platform: Behavioral / lifestyle

There is no disease-modifying therapy for NEDDFL. Management is supportive and centres on early intervention: speech and language therapy (given the disproportionate speech delay), physical and occupational therapy for motor delay and hypotonia, educational support, nutritional support for poor weight gain and feeding difficulty, and periodic monitoring for scoliosis and ophthalmologic problems.

Target Phenotypes: Delayed speech and language development HP:0000750 Motor delay HP:0001270

Show evidence (1 reference)

PMID:33522091 SUPPORT Human Clinical

"While it is unclear how significant the degree of scoliosis was within individuals, careful examination and monitoring for this clinical finding are also recommended."

Supports scoliosis surveillance. The quoted recommendation does not evaluate developmental therapies or establish their syndrome-specific efficacy.

Recombinant Human Growth Hormone

Category: Therapeutic Action: Pharmacotherapy NCIT:C15986

Agent: recombinant human growth hormone (somatropin) NCIT:C837

Platform: Protein replacement

Two boys with short stature and growth hormone deficiency on stimulation testing received rhGH in the 2023 report. One gained 25.6 cm (+1.63 SD) over 3.5 years; the other gained 2.9 cm (+0.18 SD) over four months before treatment stopped for financial reasons. These uncontrolled observations do not establish long-term efficacy, safety or benefit in individuals without growth hormone deficiency.

Target Phenotypes: Short stature HP:0004322

Show evidence (2 references)

PMID:36153657 SUPPORT Human Clinical

"Both children had short stature and responded to recombinant human growth hormone (rhGH) treatment - the first report of this therapy in NEDDFL patients."

First and, to date, principal report of growth hormone therapy in NEDDFL.

PMID:36153657 SUPPORT Human Clinical

"The salutary effect of rhGH in the NEDDFL is documented."

Authors' summary conclusion from two uncontrolled cases with no comparator; this does not establish a general treatment effect or long-term safety.

Antiseizure Medication

Category: Therapeutic Action: Pharmacotherapy NCIT:C15986

Agent: levetiracetam CHEBI:6437

Platform: Small molecule

Levetiracetam was commonly used in the selected BPTF electroclinical series and was associated with reduced seizure frequency in 67% of treated cases as reported by the authors. This observational result is not a comparative efficacy estimate. Valproate and vagus nerve stimulation were also reported in the 2021 cohort. The 27% drug-resistance figure describes the selected electroclinical series and should not be read as a rate among all individuals with NEDDFL.

Target Phenotypes: Seizure HP:0001250

Show evidence (1 reference)

PMID:38936258 SUPPORT Human Clinical

"Levetiracetam was widely used and reduced seizure frequency in 67% of the cases."

Reports an observational treatment response in selected patients, without a randomized comparison.

Cyclical Vomiting Syndrome Therapy

Category: Therapeutic Action: Pharmacotherapy NCIT:C15986

Agent: ondansetron CHEBI:7773 cyproheptadine CHEBI:4046

Platform: Small molecule

Acute treatment of cyclical vomiting episodes with ondansetron or domperidone, and prophylaxis with cyproheptadine, domperidone, or levetiracetam combined with lamotrigine, were all associated with clinical benefit in the reported BPTF series. Evidence is observational and from a single 15-individual questionnaire study.

Target Phenotypes: Episodic vomiting HP:0002572

Show evidence (1 reference)

PMID:40614698 SUPPORT Human Clinical

"Acute therapy (ondansetron or domperidone) was administered in 42.8% of cases, and prophylactic therapy was provided in 57.1% of cases with cyproheptadine, levetiracetam combined with lamotrigine, and domperidone; all therapies were associated with clinical benefit."

Observational report of benefit from acute and prophylactic CVS therapy; the uncontrolled series does not separate treatment effects from other influences on symptoms.

Genetic Counseling

Category: Counseling / Informational Action: genetic counseling Ontology label: Genetic Counseling NCIT:C15240

Platform: Behavioral / lifestyle

Counseling addresses autosomal dominant inheritance and variable expressivity. A heterozygous parent has a 50% probability of transmitting the variant in each pregnancy; this is not a quantified probability of a particular clinical severity. Parental testing can identify inherited variants in mildly affected relatives. An apparently de novo result leaves a residual recurrence risk from possible parental germline mosaicism.

Show evidence (1 reference)

PMID:33522091 SUPPORT Human Clinical

"Our study has also uncovered four cases of inherited BPTF variants, providing some insight into the penetrance and expressivity of NEDDFL."

Documented inherited variants are the basis for counseling about parental testing and recurrence risk.

Gastrostomy Feeding

Category: Therapeutic Action: Gastrostomy Tube Procedure NCIT:C157864

Platform: Surgery

Gastrostomy was used for severe feeding difficulty or failure to thrive in two reported individuals. The clinical table documents use, without quantifying nutritional benefit or procedural outcomes.

Target Phenotypes: Feeding difficulties HP:0011968

Show evidence (2 references)

PMID:33522091 SUPPORT Human Clinical

"Initial failure to thrive requiring gastrostomy; recurrent bacterial infections as a young child, requiring regular immunoglobulin infusions until age 4 y."

Table 2 documents gastrostomy for patient 9; the infection history is contextual and does not establish a general immunodeficiency mechanism.

PMID:33522091 SUPPORT Human Clinical

"Severe feeding problems requiring gastrostomy; congenitally corrected transposition of the great arteries. Mild to moderate intellectual disability (IQ 57)."

Patient 18 also required gastrostomy for feeding problems.

Scoliosis Surveillance and Bracing

Category: Therapeutic

Platform: Device

The 2021 cohort authors recommend monitoring for scoliosis. One individual had improved thoracolumbar scoliosis after previously requiring bracing; the report does not isolate the effect of bracing or establish a syndrome-specific treatment protocol.

Target Phenotypes: Scoliosis HP:0002650

Show evidence (1 reference)

PMID:33522091 SUPPORT Human Clinical

"Thoracolumbar scoliosis (improved ‐ previously required bracing) and leg length discrepancy; butterfly vertebra at T12 and questionable fusion of right posterolateral aspects of T5 and T6 vertebral bodies"

Patient 21 provides case-level evidence of brace use; improvement is not a controlled efficacy estimate.

Vagus Nerve Stimulation

Category: Therapeutic

Platform: Device

Vagal nerve stimulator placement is reported in one individual with focal epilepsy. The source describes medication-associated seizure control and recent stimulator placement, without an outcome attributable specifically to stimulation.

Target Phenotypes: Seizure HP:0001250

Show evidence (1 reference)

PMID:33522091 SUPPORT Human Clinical

"Complex focal seizures with impaired awareness of frontal lobe origin beginning at age 7 y, controlled by medication with recent vagal nerve stimulator placement"

Table 2 documents stimulator placement in patient 21 without establishing its efficacy.

🔬

Diagnosis

3

Trio Exome or Genome Sequencing

Exome sequencing, neurodevelopmental gene panels and copy-number testing have identified affected individuals. Parental testing distinguishes de novo from inherited variants and informs interpretation. The cited case series document ascertainment methods rather than establishing a syndrome-specific diagnostic yield comparison or first-line guideline.

whole exome sequencing NCIT:C101295

Show evidence (3 references)

PMID:33522091 SUPPORT Human Clinical

"Molecular testing results from exome sequencing, chromosomal microarray, or next‐generation sequencing panel were submitted by patients' healthcare providers"

Documents the diagnostic modalities through which the 26-individual expansion cohort was actually ascertained.

PMID:40415676 SUPPORT Human Clinical

"BPTF gene variants were detected using whole-exome sequencing. Family segregation analysis was performed using sanger sequencing."

Independent series confirming exome sequencing as the detection method, with Sanger segregation analysis in the family.

PMID:36153657 SUPPORT Human Clinical

"The exome sequencing was performed in two probands. Sanger sequencing was used to confirm the identified variants both in probands and their parents."

Shows the standard workflow of exome discovery plus Sanger confirmation in proband and parents.

Chromosomal Microarray for 17q24.2 Copy-Number Variants

Chromosomal microarray can detect BPTF-containing deletions, subject to assay resolution. Larger 17q24.2 deletions require assessment of other affected genes. Balanced gene-disrupting rearrangements require appropriate structural-variant testing and cannot be excluded by a normal microarray.

chromosomal microarray (array comparative genomic hybridization) NCIT:C18084

Show evidence (2 references)

PMID:28942966 SUPPORT Human Clinical

"we report eight loss-of-function and two missense variants (eight de novo and two of unknown origin) in BPTF on 17q24.2"

Establishes the 17q24.2 locus that copy-number testing must cover.

PMID:33522091 SUPPORT Human Clinical

"Molecular testing results from exome sequencing, chromosomal microarray, or next‐generation sequencing panel were submitted by patients' healthcare providers"

Confirms chromosomal microarray as one of the modalities that identified individuals in the expansion cohort.

ACMG/AMP Variant Interpretation with Parental Testing

A molecular diagnosis requires a pathogenic or likely pathogenic BPTF variant interpreted with phenotype, inheritance, population frequency, transcript context and the expected effect of the allele. The 2021 cohort reported 11 pathogenic, seven likely pathogenic and two uncertain variants. A VUS alone does not establish the diagnosis. The two missense variants in the 2025 report were also VUS, despite severe findings in carriers, illustrating why phenotype severity alone cannot establish pathogenicity. Truncating and copy-number alleles likewise require appropriate interpretation.

genetic testing NCIT:C15709

Explicit negatives, recorded so their absence is not mistaken for a curation gap. (1) There are no formal consensus diagnostic criteria for NEDDFL; diagnosis is a compatible phenotype plus molecular confirmation. (2) There is no diagnostic biochemical, enzymatic, imaging, or circulating biomarker - a normal brain MRI in particular does not exclude the diagnosis, since most imaged individuals in the expansion cohort had normal studies. (3) No validated functional assay and no DNA-methylation episignature has been established for BPTF, despite NEDDFL being a chromatinopathy where an episignature might be expected; RNA sequencing and proteomics for resolving difficult variants remain investigational. (4) No newborn or general population screening exists; cascade testing is appropriate once a familial pathogenic variant is known.

Show evidence (2 references)

PMID:33522091 SUPPORT Human Clinical

"Variants were interpreted as pathogenic (11), likely pathogenic (7), or VUS (2) based on the current ACMG criteria."

Documents ACMG/AMP classification as the interpretation framework and the residual VUS rate.

PMID:33522091 SUPPORT Human Clinical

"it is anticipated that the finding of missense variants in BPTF may present a diagnostic challenge for practitioners, particularly in individuals with mild phenotypes"

The authors flag missense variants as the principal interpretation difficulty, supporting the caution that a missense VUS alone is not diagnostic.

📊

Prevalence

1

Worldwide

Cases In Literature Ultra Rare

The 2023 growth-hormone report summarized 36 previously reported individuals and added two. Later series include previously published as well as new individuals, so their totals cannot simply be added. No population prevalence estimate is established.

Show evidence (2 references)

PMID:36153657 SUPPORT Human Clinical

"To date, there are only 36 cases reported in the literature, and patients mainly presented with a developmental delay, language delay, and microcephaly."

Provides the published case count underpinning the ultra-rare classification.

PMID:40415676 SUPPORT Human Clinical

"Neurodevelopmental disorder with dysmorphic facies and distal limb anomalies (NEDDFL, OMIM no #617755) is an ultra-rare syndrome associated with heterozygous pathogenic variants in the BPTF gene."

Independent characterization of the disorder as ultra-rare.

🔀

Differential Diagnoses

3

Conditions with similar clinical presentations that must be differentiated from BPTF-Related Neurodevelopmental Disorder:

Neurodevelopmental disorder with dysmorphic facies and distal skeletal anomalies (ZMIZ1) MONDO:0032855

Overlapping Features A separate autosomal dominant neurodevelopmental entity caused by heterozygous ZMIZ1 variants. Its MONDO label differs from this disorder's by a single word ("skeletal" versus "limb"), which makes it the single highest named-entity-confusion risk for NEDDFL in any label- or text-based search.

Distinguishing Features

Molecular: ZMIZ1 versus BPTF (hgnc:3581). The gene is the only reliable discriminator; confirm the causative gene before importing any cohort data published under either "dysmorphic facies and distal ... anomalies" phrasing.
Nomenclature: the near-identical labels are the hazard, not the phenotypes. Both are dominant neurodevelopmental syndromes with dysmorphism and distal appendicular findings.

Silver-Russell syndrome

Overlapping Features A clinical phenocopy hazard rather than a nomenclature hazard: the combination of small-for-gestational-age birth, poor postnatal growth, a small triangular face, and feeding difficulty can prompt an initial diagnosis of Silver-Russell syndrome in a child later found to have BPTF disruption. At least one adult carried the Silver-Russell label for 35 years before BPTF disruption was identified.

Distinguishing Features

NEDDFL has postnatal (secondary) microcephaly, whereas relative macrocephaly for body size is characteristic of Silver-Russell syndrome.
NEDDFL has prominent speech delay and intellectual disability; cognition is typically preserved or only mildly affected in Silver-Russell syndrome.
Silver-Russell syndrome is most often caused by 11p15 loss of methylation or maternal uniparental disomy of chromosome 7, neither of which involves BPTF.

📊

Related Datasets

1

BPTF is essential for murine neocortical development geo:GSE154700

Bulk forebrain RNA sequencing comparing Bptf Emx1-Cre conditional knockout and control mice at E13.5 and birth. GEO contains four control and four knockout samples at each stage, totaling 16 samples.

Mus musculus BULK RNA SEQ n=16 Illumina HiSeq 4000 and Illumina NovaSeq 6000

Conditions: E13.5 control and Bptf forebrain conditional knockout P0 control and Bptf forebrain conditional knockout

PMID:35604347

GEO GSE154700 lists 16 samples and two platforms. The overall-design field mentions P0 only, but the sample list also contains eight E13.5 samples. Bulk expression at birth is affected by altered neuronal abundance and microglial accumulation; changes are not necessarily cell-intrinsic or direct BPTF targets. This complete-loss mouse dataset is not a human heterozygous disease transcriptome.

🧫

Experimental Models

2

Bptf-null mouse embryonic stem cells and rescued embryoid bodies OTHER

Bptf-null embryonic stem cells remain viable but differentiate abnormally. Embryoid bodies fail to form a normal outer endodermal layer and show impaired lineage-marker induction, rescued by retargeting a functional Bptf allele. Microarray experiments under LIF maintenance, LIF withdrawal and retinoic-acid differentiation show context-dependent activation and repression, including derepression of Hox clusters. Activin experiments preserve Smad2 phosphorylation but impair selected target-gene induction and Snf2h/l enhancer recruitment.

Organism

Mus musculus NCBITaxon:10090

Cell source

Engineered mouse embryonic stem-cell lines derived from CJ7 cells

Culture

Embryonic stem-cell culture, LIF withdrawal or retinoic-acid differentiation, and nine-day embryoid-body differentiation

Publication

PMID:18974875

Pathograph links

Dysregulated Developmental Gene Transcription recapitulates fidelity: moderate Directly measures Bptf-dependent transcription during differentiation and ligand stimulation.

Limitations: Complete-loss mouse stem cells and early embryonic differentiation are not patient-derived heterozygous neural models. The findings do not establish a universal increase in apoptosis after BPTF loss.

Readouts

Lineage-marker induction after Bptf restoration

Mesodermal and endodermal transcriptional responses during embryoid-body differentiation recover after retargeting a functional allele.

Direction: RESTORED

Activin-responsive target-gene induction

Cer1, Gsc and T induction is impaired in Bptf-null cells despite retained Smad2 phosphorylation.

Direction: DECREASED

Show evidence (3 references)

PMID:18974875 SUPPORT In Vitro

"Reintroduction of BptfFloxed-Neo rescued the induction of mesoderm and endoderm markers during embryoid differentiation."

Restoring a functional Bptf allele rescued lineage-marker induction, supporting a Bptf-dependent differentiation defect.

+ 2 more references

The 2008 paper provides microarray and analysis data in a supplementary XLS file; no GEO accession was identified in the cached full text. NURF can activate or repress different gene sets depending on differentiation conditions.

Show evidence (4 references)

PMID:18974875 SUPPORT In Vitro

"Reintroduction of BptfFloxed-Neo rescued the induction of mesoderm and endoderm markers during embryoid differentiation."

Restoring a functional Bptf allele rescued lineage-marker induction, supporting a Bptf-dependent differentiation defect.

PMID:18974875 SUPPORT In Vitro

"TUNEL negative Bptf mutant (−/−) and wild type (+/+) cells have similar staining for proliferation markers PCNA and phosphorylated histone H3."

The embryoid-body phenotype was not accompanied by generalized increased apoptosis or reduced proliferation-marker staining.

PMID:18974875 SUPPORT In Vitro

"ES cells readily responded to activin-A as monitored by the phosphorylation of Smad2 ... Genes requiring Bptf for full activation include Cer1, Gsc and T"

Activin-induced Smad2 phosphorylation was preserved, while selected downstream transcriptional responses depended on Bptf.

+ 1 more reference

P19 Bptf-knockdown Smad-response reporter model CELL_LINE

Bptf knockdown reduces TGF-beta- and activin-responsive reporter transcription in P19 cells. Reporter activation remains impaired when the pathway is driven with constitutively active receptor and Smad constructs, supporting a nuclear co-regulatory role.

Organism

Mus musculus NCBITaxon:10090

Cell source

Mouse P19 embryonal carcinoma cell line

Culture

siRNA knockdown with Smad-binding-element or activin-response-element luciferase reporters

Publication

PMID:18974875

Pathograph links

Dysregulated Developmental Gene Transcription recapitulates fidelity: low Tests a specific transcriptional consequence of Bptf depletion.

Limitations: Transformed mouse cells with artificial reporters do not establish this pathway as the cause of human neurodevelopmental or gastrointestinal features.

Readouts

Smad-response reporter activity

Luciferase output falls after Bptf siRNA under ligand stimulation or constitutive receptor/Smad activation.

Direction: DECREASED

Show evidence (2 references)

PMID:18974875 SUPPORT In Vitro

"Under conditions of Bptf knockdown, we observed a significant reduction in luciferase activity from both reporters"

Bptf knockdown reduced both minimal Smad-binding-element and activin-response-element reporter activity in P19 cells.

+ 1 more reference

Show evidence (2 references)

PMID:18974875 SUPPORT In Vitro

"Under conditions of Bptf knockdown, we observed a significant reduction in luciferase activity from both reporters"

Bptf knockdown reduced both minimal Smad-binding-element and activin-response-element reporter activity in P19 cells.

PMID:18974875 SUPPORT In Vitro

"Knockdown of Bptf in P19 cells renders SBE Smad responsive elements unresponsive to constitutively activated Smad transcription factors."

Reporter impairment persists with constitutive receptor/Smad activation, consistent with a downstream transcriptional requirement.

🐁

Animal Models

3

Bptf forebrain-conditional knockout mouse Conditional knockout mouse model of NEDDFL

Forebrain-specific Bptf knockout generated with Emx1-Cre causes severe cortical hypoplasia, increased death of newly postmitotic neurons and altered cortical neuronal marker distribution. A reduced 24-hour cell-cycle exit fraction suggests delayed differentiation or a longer cycle; cycle length was not directly timed. Brain weight is reduced at birth, whereas body weight diverges after birth. The mice survive to adulthood, with largely nonprogressive gross anatomy; normal home-cage appearance is not a formal behavioral or seizure assessment.

Species

Mus musculus

Genotype

Emx1-Cre forebrain-conditional Bptf knockout (Bptf cKO)

Pathograph links

Delayed Neural Progenitor Cell-Cycle Exit recapitulates fidelity: moderate Measures this candidate mechanism in a complete forebrain conditional knockout.

Limitations: The complete tissue-specific knockout differs from human heterozygous BPTF disease. Human confirmation is lacking.

Readouts

Fraction of labeled cells exiting the cycle over 24 hours

EdU-positive, Ki67-negative fraction after an E14.5 pulse and E15.5 harvest.

Direction: DECREASED

Interpretation: Reduced cycle exit supports delayed differentiation or longer cycle duration; cycle length itself was inferred.

Show evidence (1 reference)

url:https://pmc.ncbi.nlm.nih.gov/articles/PMC9558838/ SUPPORT Model Organism

"Taken together, the cortical progenitor cells of the ... cKO mice show no blocks in the cell cycle with similar cell proportions in the S- and M-phase to the control samples. However, fewer cells exited the cell cycle in a 24-h period suggesting that cell cycle length was prolonged, which could..."

Separates the measured cell-cycle exit fraction from the inferred cycle length and preserves negative proliferation findings.

Increased Neuronal Apoptosis recapitulates fidelity: moderate Measures this candidate mechanism in a complete forebrain conditional knockout.

Limitations: The complete tissue-specific knockout differs from human heterozygous BPTF disease. Human confirmation is lacking.

Readouts

Cell death in intermediate zone and cortical plate

Cleaved-caspase-3 staining in differentiating neuronal regions; ventricular-zone levels were largely unchanged at E15.5.

apoptotic process GO:0006915

Direction: INCREASED

Interpretation: The spatial distribution implicates newly postmitotic neurons rather than proving generalized progenitor death.

Show evidence (1 reference)

url:https://pmc.ncbi.nlm.nih.gov/articles/PMC9558838/ SUPPORT Model Organism

"We conclude from this data that a high incidence of cell death is a major contributor to the reduction in cortical size and that this occurs as the neurons become postmitotic, initiate their terminal differentiation program, and migrate toward their final laminar position."

Localizes the major cell-death contribution to differentiating neurons in the conditional-null model.

Impaired Cortical Neuron Fate Specification recapitulates fidelity: moderate Measures this candidate mechanism in a complete forebrain conditional knockout.

Limitations: The complete tissue-specific knockout differs from human heterozygous BPTF disease. Human confirmation is lacking.

Readouts

Ctip2-high layer V neuron proportion

Ctip2-high layer V cell counts are markedly reduced, with changes in Ctip2-low cell distribution across layers.

Direction: DECREASED

Interpretation: Layer-specific marker counts reflect altered identity or maturation as well as possible changes in cell number; they are not a direct birth-rate measurement.

Layer-specific Ctip2 regulation

Ctip2 expression and layer distribution change despite preserved bulk Ctip2 protein and transcript levels and no reduction in birth-dated EdU/Ctip2-colabeled cells.

cerebral cortex neuron differentiation GO:0021895

Direction: ALTERED

Interpretation: The combination supports abnormal terminal differentiation and marker regulation rather than absence of this neuronal class.

Show evidence (2 references)

url:https://pmc.ncbi.nlm.nih.gov/articles/PMC9558838/ SUPPORT Model Organism

"Immunoblots suggested the overall levels of Ctip2 were not markedly different than in the control extracts"

Preserves the negative bulk-protein result despite altered layer-specific Ctip2 staining.

+ 1 more reference

Cortical Hypoplasia recapitulates fidelity: moderate Reduced cortical size is directly observed in the conditional-null model.

Limitations: Complete forebrain loss differs from human heterozygous BPTF variants. Human MRI abnormalities are heterogeneous.

Readouts

Cortical size

Histological cortical size and forebrain weight are reduced relative to controls.

Direction: DECREASED

Interpretation: Direct model evidence for tissue hypoplasia, without establishing the same anatomical lesion in every human case.

Show evidence (2 references)

PMID:35604347 SUPPORT Model Organism

"The Bptf cKO mice were born in normal Mendelian ratios, survived to adulthood but were smaller in size with severe cortical hypoplasia."

Establishes cortical hypoplasia with reduced body size as the tissue-level phenotype of forebrain Bptf loss.

+ 1 more reference

Notes

The larger-brain Smarca1 comparator in the original study is the exon-6 deletion allele producing internally truncated protein. Later complete-null experiments showed near-normal cortical size and support compensation by SMARCA5. These allele-specific effects limit use of an ATPase perturbation as a substitute for BPTF loss. Conditional heterozygotes also showed increased cleaved-caspase-3 staining at P7, so the study does not establish complete absence of heterozygous effects.

Show evidence (2 references)

PMID:35604347 SUPPORT Model Organism

"To model the NEDDFL syndrome, we generated forebrain-specific Bptf knockout (Bptf conditional Knockout (cKO)) mice."

Establishes the model's purpose and construction.

PMID:35604347 SUPPORT Model Organism

"Surprisingly, ablation of Smarca1 resulted in mice with enlarged brains, a direct contrast to the phenotype of NEDDFL patients."

The original paper summarizes the enlarged-brain comparator; the subsequent study distinguishes the exon-6 deletion allele from a complete Smarca1 null.

bptf CRISPR F0 crispant zebrafish CRISPR F0 knockout zebrafish model

CRISPR-Cas9 knockout of zebrafish bptf produces F0 mutant larvae with significantly reduced head size, increased apoptosis by TUNEL staining, and a substantially increased ceratohyal angle indicating abnormal craniofacial patterning (PMID:28942966). This model recapitulates both the microcephaly and the craniofacial dimensions of NEDDFL.

Species

Danio rerio

Genotype

CRISPR-Cas9 bptf F0 crispant

Pathograph links

Reduced Brain Growth partially recapitulates fidelity: moderate Reduced head size in bptf F0 larvae is the cross-species correlate of the human microcephaly.

Limitations: F0 crispants are mosaic genome-edited larvae. Reduced head size does not establish human postnatal timing or a defined heterozygous dosage response.

Readouts

Larval head size

Head size of bptf F0 crispant larvae versus control larvae.

Direction: DECREASED

Interpretation: Significantly reduced head size is the model's microcephaly readout; it indexes reduced brain growth but not the postnatal timing of the human phenotype.

Show evidence (1 reference)

PMID:28942966 SUPPORT Model Organism

"Using CRISPR-Cas9 genome editing of bptf in zebrafish to induce a loss of gene function, we observed a significant reduction in head size of F0 mutants compared to control larvae."

Reduced larval head size supports a developmental role for bptf but does not capture the postnatal timing of some human microcephaly presentations or quantify human heterozygous effects.

Disrupted Craniofacial and Limb Patterning partially recapitulates Increased ceratohyal angle is an established quantitative readout of disrupted craniofacial patterning, and is the direct experimental support for the craniofacial arm of this node.

Limitations: Supports the craniofacial arm only. No model has yet demonstrated the distal limb arm of this node, which is why the node is marked PROVISIONAL.

Readouts

Ceratohyal angle

Angle of the ceratohyal cartilage of the craniofacial skeleton in bptf F0 crispants versus controls.

Direction: INCREASED

Interpretation: A substantially widened ceratohyal angle is the established quantitative index of abnormal craniofacial patterning in zebrafish.

Show evidence (1 reference)

PMID:28942966 SUPPORT Model Organism

"we observed a substantial increase of the ceratohyal angle of the craniofacial skeleton in bptf F0 mutants, indicating abnormal craniofacial patterning"

Direct experimental demonstration of disrupted craniofacial patterning on bptf loss.

Show evidence (1 reference)

PMID:28942966 SUPPORT Model Organism

"Using CRISPR-Cas9 genome editing of bptf in zebrafish to induce a loss of gene function, we observed a significant reduction in head size of F0 mutants compared to control larvae."

Establishes the zebrafish model and its microcephaly readout.

Constitutive Bptf-null mouse embryo Constitutive null mouse embryo

Gene-trap and exon-2-deletion homozygotes develop postimplantation growth defects, fail to establish a functional distal/anterior visceral endoderm and primitive streak, and are resorbed by E8.5. Mitotic-marker staining is reduced without a generalized increase in TUNEL staining. These findings establish early embryonic gene essentiality, not the phenotype of human heterozygous disease.

Species

Mus musculus

Genotype

Homozygous Bptf gene-trap or exon-2 deletion; equivalent early embryonic phenotypes

Pathograph links

BPTF Haploinsufficiency perturbs fidelity: low Perturbs Bptf through complete loss, providing an essentiality comparison for the human heterozygous disorder. It does not quantify a heterozygous dose-response relationship.

Limitations: Both alleles are disrupted, whereas affected humans typically carry one pathogenic allele. The study also reports a maternal effect on embryo survival in gene-trap heterozygous females, without preferential loss of heterozygous offspring; this is distinct from a demonstrated heterozygous neurodevelopmental phenotype.

Readouts

Post-implantation embryonic survival

Survival of constitutive Bptf-null embryos, which show post-implantation growth defects and are resorbed by E8.5.

Direction: DECREASED

Interpretation: Complete-loss embryonic lethality demonstrates essentiality and cannot establish the consequences of a heterozygous variant.

Show evidence (1 reference)

PMID:18974875 SUPPORT Model Organism

"Bptf mutants manifest growth defects at the post-implantation stage and are reabsorbed by E8.5."

Demonstrates embryonic essentiality after complete Bptf loss, without measuring human haploinsufficiency.

Show evidence (1 reference)

PMID:18974875 SUPPORT Model Organism

"Bptf mutants manifest growth defects at the post-implantation stage and are reabsorbed by E8.5."

Demonstrates embryonic essentiality after complete Bptf loss, without measuring human haploinsufficiency.

{ }

Source YAML

click to show

name: BPTF-Related Neurodevelopmental Disorder
creation_date: "2026-08-15T00:00:00Z"
category: Mendelian
synonyms:
- NEDDFL
- neurodevelopmental disorder with dysmorphic facies and distal limb anomalies
- BPTF haploinsufficiency
description: >-
  Neurodevelopmental disorder with dysmorphic facies and distal limb anomalies (NEDDFL, MONDO:0060596,
  OMIM:617755) is an ultra-rare autosomal dominant syndrome caused by heterozygous loss-of-function variants
  in BPTF (hgnc:3581) at 17q24.2. BPTF encodes the bromodomain PHD finger transcription factor, the largest
  and NURF-exclusive subunit of the nucleosome remodeling factor (NURF), an ISWI-family ATP-dependent
  chromatin-remodeling complex whose catalytic ATPase can be SMARCA1/SNF2L or SMARCA5/SNF2H. BPTF reads
  the activating chromatin marks H3K4me3 (via its PHD finger) and H4K16ac (via its bromodomain) and thereby
  couples those marks to ATP-dependent nucleosome sliding at developmental gene promoters. Because BPTF
  is dosage-sensitive, a single null allele is sufficient to produce disease. The clinical core is developmental
  delay/intellectual disability with disproportionate speech and language delay, postnatal (secondary)
  microcephaly, poor growth, a mild but recognizable dysmorphic facial gestalt (prominent or bulbous nasal
  tip, prominent nasal bridge, pointed chin), and mild distal limb anomalies of the hands and feet (cutaneous
  2-3 toe syndactyly, sandal gap, fifth-finger clinodactyly). Phenotypic expansion since the 2017 founding
  cohort has added ophthalmologic abnormalities, scoliosis and other skeletal findings, mild structural
  brain abnormalities, early-childhood-onset epilepsy, and cyclical vomiting syndrome. Most variants arise
  de novo, but transmitted alleles from mildly affected parents establish variable expressivity. Management
  is supportive; there is no disease-modifying therapy.
notes: >-
  Published frequencies derive from small, clinically ascertained cohorts with incomplete assessments
  and overlapping participants. Counts for composite findings, such as developmental delay and/or intellectual
  disability, do not estimate each component separately. Congenital and postnatal microcephaly both occur.
  Clinical findings in carriers of variants of uncertain significance require interpretation separately
  from established BPTF loss-of-function disease.
disease_term:
  preferred_term: NEDDFL
  term:
    id: MONDO:0060596
    label: neurodevelopmental disorder with dysmorphic facies and distal limb anomalies
parents:
- Mendelian neurodevelopmental disorder
- Chromatin remodeling disorder
references:
- reference: PMID:28942966
  title: "Haploinsufficiency of the Chromatin Remodeler BPTF Causes Syndromic Developmental and Speech Delay, Postnatal Microcephaly, and Dysmorphic Features."
- reference: PMID:33522091
  title: "Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies."
- reference: PMID:36153657
  title: "The effect of growth hormone treatment in children with novel BPTF gene variants: A report of two cases and literature review."
- reference: PMID:41213919
  title: Pathogenic variants in SMARCA1 cause an X-linked neurodevelopmental disorder modulated by NURF complex composition.
- reference: url:https://pmc.ncbi.nlm.nih.gov/articles/PMC9558838/
  title: Generation of a mouse model of the neurodevelopmental disorder with dysmorphic facies and distal limb anomalies syndrome - PMC
classifications:
  harrisons_chapter:
  - classification_value: NEUROLOGIC
    notes: >-
      The dominant clinical burden is neurodevelopmental: developmental delay,
      intellectual disability, disproportionate speech delay, hypotonia,
      microcephaly, and (in a minority) epilepsy.
    evidence:
    - reference: PMID:28942966
      reference_title: "Haploinsufficiency of the Chromatin Remodeler BPTF Causes Syndromic Developmental and Speech Delay, Postnatal Microcephaly, and Dysmorphic Features."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        who manifest variable degrees of developmental delay/intellectual
        disability (10/10), speech delay (10/10), postnatal microcephaly (7/9),
        and dysmorphic features (9/10)
      explanation: >-
        The defining cohort establishes developmental delay, intellectual
        disability, and speech delay as near-universal features, supporting a
        neurologic chapter assignment.
  - classification_value: GENETICS_ENVIRONMENT_DISEASE
    notes: >-
      NEDDFL is a monogenic, dosage-sensitivity (haploinsufficiency) disorder of
      a chromatin-remodeling complex subunit.
    evidence:
    - reference: PMID:28942966
      reference_title: "Haploinsufficiency of the Chromatin Remodeler BPTF Causes Syndromic Developmental and Speech Delay, Postnatal Microcephaly, and Dysmorphic Features."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        our data demonstrate the pathogenic role of BPTF haploinsufficiency in
        syndromic neurodevelopmental anomalies and extend the clinical spectrum
        of human disorders caused by ablation of chromatin remodeling complexes
      explanation: >-
        Explicitly frames the disorder as a genetic disease of chromatin
        remodeling complex dosage.
inheritance:
- name: Autosomal dominant inheritance
  inheritance_term:
    preferred_term: Autosomal dominant inheritance
    term:
      id: HP:0000006
      label: Autosomal dominant inheritance
  description: >-
    NEDDFL results from a heterozygous loss-of-function allele of BPTF; the gene
    is dosage-sensitive and a single null allele is sufficient to cause disease.
    Most reported variants arose de novo, but transmission from a mildly
    affected parent has been documented in four families, establishing autosomal
    dominant inheritance with variable expressivity rather than exclusively
    de novo occurrence. Transmitting parents range from isolated microcephaly
    without reported developmental delay, through learning disability with
    independent adult function, to a phenotype comparable to that of the
    proband. Penetrance has not been quantified.
  expressivity: VARIABLE
  evidence:
  - reference: PMID:28942966
    reference_title: "Haploinsufficiency of the Chromatin Remodeler BPTF Causes Syndromic Developmental and Speech Delay, Postnatal Microcephaly, and Dysmorphic Features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      we report eight loss-of-function and two missense variants (eight de novo
      and two of unknown origin) in BPTF on 17q24.2
    explanation: >-
      Establishes heterozygous, predominantly de novo variation at a single
      locus as the molecular basis, consistent with autosomal dominant
      inheritance.
  - reference: PMID:33522091
    reference_title: "Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Our study has also uncovered four cases of inherited BPTF variants,
      providing some insight into the penetrance and expressivity of NEDDFL.
    explanation: >-
      Documented parent-to-child transmission confirms dominant inheritance and
      demonstrates that the disorder is not exclusively de novo.
  - reference: PMID:33522091
    reference_title: "Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The histories reported in these patients and the presence of inherited
      pathogenic variants in BPTF do suggest a pattern of variable expressivity
      in NEDDFL.
    explanation: >-
      Directly supports the recorded VARIABLE expressivity of the dominant
      allele.

genetic:
- name: BPTF
  gene_term:
    preferred_term: BPTF
    term:
      id: hgnc:3581
      label: BPTF
  relationship_type: CAUSATIVE
  variant_origin: GERMLINE
  association: >-
    Heterozygous pathogenic variants disrupting BPTF cause an autosomal dominant neurodevelopmental disorder,
    with haploinsufficiency as the principal mechanism. Reported allele classes include frameshift, nonsense,
    splice-site, exon or whole-gene deletions, gene-disrupting rearrangements, in-frame deletions and
    missense substitutions. Clinical severity cannot be reliably predicted from allele class alone. The
    two missense variants in the 2025 four-person report were classified as variants of uncertain significance,
    so that series does not establish their pathogenicity or a missense-specific severe phenotype.
  notes: >-
    Variants occur throughout BPTF. Both de novo and inherited constitutional variants are reported; the
    2021 cohort included four transmissions from apparently non-mosaic parents. Penetrance is not quantified.
    Variant nomenclature in the literature uses NM_004459.6 or NM_182641.4 and must retain its source
    transcript. Somatic BPTF alterations in cancer are a distinct literature.
  evidence:
  - reference: PMID:28942966
    reference_title: "Haploinsufficiency of the Chromatin Remodeler BPTF Causes Syndromic Developmental and Speech Delay, Postnatal Microcephaly, and Dysmorphic Features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      we report eight loss-of-function and two missense variants (eight de novo
      and two of unknown origin) in BPTF on 17q24.2
    explanation: >-
      Establishes BPTF at 17q24.2 as the causative locus and shows the
      loss-of-function-dominant allelic spectrum.
  - reference: PMID:33522091
    reference_title: "Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Our analysis identified 20 novel, distinct variants in BPTF (Table 1)
      distributed throughout the gene (Figure 1), including 14 de novo and four
      inherited.
    explanation: >-
      Documents variants distributed across BPTF and the reported inheritance counts; this sample does
      not establish the absence of recurrent alleles.
  - reference: PMID:40415676
    reference_title: "Effects of the Missense Variants on Complete Phenotype and Splicing Variant on Severe Growth Retardation in the BPTF Gene."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      We detected two novel missense variants in patients presenting all
      phenotypic characteristics of the BPTF-related NEDDFL syndrome severely,
      including severe ID, distinctive facial features, and anomalies of the
      hands and feet.
    explanation: >-
      The authors describe severe findings in missense carriers, but their full-text results classify
      both missense variants as VUS. These observations do not establish a genotype-severity relationship.

  - reference: PMID:40415676
    reference_title: Effects of the Missense Variants on Complete Phenotype and Splicing Variant on Severe Growth Retardation in the BPTF Gene.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: WES analysis revealed three different variants (one pathogenic and two uncertain significance).
    explanation: >-
      The full-text classification limits interpretation of the missense observations and severity hypotheses.
prevalence:
- population: Worldwide
  measure_type: CASES_IN_LITERATURE
  prevalence_class: ULTRA_RARE
  notes: >-
    The 2023 growth-hormone report summarized 36 previously reported individuals and added two. Later
    series include previously published as well as new individuals, so their totals cannot simply be added.
    No population prevalence estimate is established.
  evidence:
  - reference: PMID:36153657
    reference_title: "The effect of growth hormone treatment in children with novel BPTF gene variants: A report of two cases and literature review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      To date, there are only 36 cases reported in the literature, and patients
      mainly presented with a developmental delay, language delay, and
      microcephaly.
    explanation: >-
      Provides the published case count underpinning the ultra-rare
      classification.
  - reference: PMID:40415676
    reference_title: "Effects of the Missense Variants on Complete Phenotype and Splicing Variant on Severe Growth Retardation in the BPTF Gene."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Neurodevelopmental disorder with dysmorphic facies and distal limb anomalies (NEDDFL, OMIM no #617755) is an ultra-rare syndrome associated with heterozygous pathogenic variants in the BPTF gene."
    explanation: >-
      Independent characterization of the disorder as ultra-rare.

pathophysiology:
- name: BPTF Haploinsufficiency
  biological_scale: MOLECULAR
  mechanism_confidence: ESTABLISHED
  description: >-
    Heterozygous pathogenic loss-of-function variants reduce functional BPTF dosage. The clinical and
    genetic evidence supports haploinsufficiency, but it does not establish an identical 50% protein reduction
    for every allele or tissue. BPTF is shared by NURF complexes containing either SMARCA1 or SMARCA5;
    the consequences of human heterozygosity cannot be equated with complete Bptf loss in mouse forebrain.
  gene:
    preferred_term: BPTF
    term:
      id: hgnc:3581
      label: BPTF
  downstream:
  - target: Impaired NURF Chromatin-Remodeling Activity
    causal_link_type: DIRECT
    description: >-
      Reduced functional BPTF is expected to impair NURF-dependent chromatin regulation; the amount of
      assembled complex in patient neural cells has not been quantified in the cited studies.
  evidence:
  - reference: PMID:28942966
    reference_title: "Haploinsufficiency of the Chromatin Remodeler BPTF Causes Syndromic Developmental and Speech Delay, Postnatal Microcephaly, and Dysmorphic Features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      our data demonstrate the pathogenic role of BPTF haploinsufficiency in
      syndromic neurodevelopmental anomalies and extend the clinical spectrum
      of human disorders caused by ablation of chromatin remodeling complexes
    explanation: >-
      States haploinsufficiency as the disease mechanism.
  - reference: PMID:33522091
    reference_title: "Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Haploinsufficiency of BPTF in humans leads to the clinical entity known as
      neurodevelopmental disorder with dysmorphic facies and distal limb
      anomalies (NEDDFL, MIM#617755).
    explanation: >-
      Links reduced BPTF dosage directly to the named clinical entity.

- name: Impaired NURF Chromatin-Remodeling Activity
  biological_scale: MOLECULAR
  mechanism_confidence: PROVISIONAL
  description: >-
    BPTF is the chromatin-reader subunit of NURF, which can contain SMARCA1/SNF2L or SMARCA5/SNF2H. Its
    PHD finger recognizes H3K4me3 and its bromodomain recognizes acetylated histones. Biochemical evidence
    links histone recognition to NURF recruitment and remodeling. The 2006 recruitment experiment depleted
    H3K4me3 rather than modeling a heterozygous patient BPTF allele. Mouse genetic comparisons support
    different developmental roles and compensatory capacities of the NURF ATPases; direct NURF subunit
    exchange in human BPTF-haploinsufficient cortex remains unmeasured.
  biological_processes:
  - preferred_term: ATP-dependent chromatin remodeling
    term:
      id: GO:0006338
      label: chromatin remodeling
    modifier: DECREASED
  molecular_functions:
  - preferred_term: BPTF PHD finger reading of H3K4me3
    term:
      id: GO:0140002
      label: histone H3K4me3 reader activity
    modifier: DECREASED
  - preferred_term: NURF nucleosome sliding
    term:
      id: GO:0140750
      label: nucleosome array spacer activity
    modifier: DECREASED
  downstream:
  - target: Dysregulated Developmental Gene Transcription
    causal_link_type: DIRECT
    description: >-
      Loss of NURF-mediated nucleosome remodeling at developmental promoters
      changes the transcriptional output of those genes.
  evidence:
  - reference: PMID:28942966
    reference_title: "Haploinsufficiency of the Chromatin Remodeler BPTF Causes Syndromic Developmental and Speech Delay, Postnatal Microcephaly, and Dysmorphic Features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Bromodomain PHD finger transcription factor (BPTF) is the largest subunit
      of nucleosome remodeling factor (NURF), a member of the ISWI
      chromatin-remodeling complex.
    explanation: >-
      Establishes BPTF's identity as the largest NURF subunit within the ISWI
      family.
  - reference: PMID:16728976
    reference_title: "A PHD finger of NURF couples histone H3 lysine 4 trimethylation with chromatin remodelling."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      Here we show that a plant homeodomain (PHD) finger of nucleosome
      remodelling factor (NURF), an ISWI-containing ATP-dependent
      chromatin-remodelling complex, mediates a direct preferential association
      with H3K4me3 tails.
    explanation: >-
      Defines the molecular reader function of the BPTF PHD finger that is lost
      when BPTF dosage falls.
  - reference: PMID:16728976
    reference_title: "A PHD finger of NURF couples histone H3 lysine 4 trimethylation with chromatin remodelling."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      Depletion of H3K4me3 causes partial release of the NURF subunit, BPTF
      (bromodomain and PHD finger transcription factor), from chromatin and
      defective recruitment of the associated ATPase, SNF2L (also known as ISWI
      and SMARCA1), to the HOXC8 promoter.
    explanation: >-
      Demonstrates the mechanistic coupling between BPTF chromatin engagement
      and delivery of the SNF2L remodeling ATPase to a developmental promoter.
  - reference: PMID:33522091
    reference_title: "Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      BPTF in particular facilitates this interaction by the preferential
      binding of its plant homeodomain (PHD) finger to the tails of the
      trimethylated lysine 4 of histone H3 (H3K4me3) and binding of its
      bromodomain to the acetylated lysine 16 of histone H4 (H4K16ac)
    explanation: >-
      Records both reader modules of BPTF in the disease-specific literature.

  - reference: PMID:41213919
    reference_title: Pathogenic variants in SMARCA1 cause an X-linked neurodevelopmental disorder modulated by NURF complex composition.
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: Moreover, all combinations of double mutants (Smarca1/Smarca5 dKO, Smarca5/Smarca1ex6del, and Smarca5/Bptf dKO) resulted in a phenotype no more severe than the Bptf mutants alone (Fig. 8A).
    explanation: >-
      Mouse genetic comparisons support a central role for Bptf-containing remodeling complexes in cortical
      growth. These are complete or combined loss models, not measurements of human heterozygous complex
      activity.
- name: Dysregulated Developmental Gene Transcription
  biological_scale: MOLECULAR
  mechanism_confidence: PROVISIONAL
  description: >-
    Bptf loss alters developmental gene expression in experimental systems. In conditional-null cortex,
    transcriptomic changes include neuronal fate regulators and stress-response pathways. MYC-binding-site
    enrichment is computational and does not demonstrate BPTF/MYC occupancy or a causal interaction in
    patient neurons. Postnatal bulk expression differences also reflect changed cell populations, including
    microglia. Embryonic stem-cell experiments additionally show context-dependent activation and repression
    of developmental genes and impaired Smad-responsive transcription despite preserved Smad2 phosphorylation.
    These findings are model-specific, not a demonstrated universal failure of upstream TGF-beta signaling.
  biological_processes:
  - preferred_term: regulation of transcription by RNA polymerase II
    term:
      id: GO:0006357
      label: regulation of transcription by RNA polymerase II
    modifier: ABNORMAL
  downstream:
  - target: Delayed Neural Progenitor Cell-Cycle Exit
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
  - target: Increased Neuronal Apoptosis
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
  - target: Impaired Cortical Neuron Fate Specification
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
  - target: Disrupted Craniofacial and Limb Patterning
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
  - target: Somatic Growth Impairment
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
  evidence:
  - reference: PMID:16728976
    reference_title: "A PHD finger of NURF couples histone H3 lysine 4 trimethylation with chromatin remodelling."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      Loss of BPTF in Xenopus embryos mimics WDR5 loss-of-function phenotypes,
      and compromises spatial control of Hox gene expression.
    explanation: >-
      Directly demonstrates that BPTF loss dysregulates spatial developmental
      gene expression in a vertebrate embryo.
  - reference: PMID:18974875
    reference_title: "Essential role of chromatin remodeling protein Bptf in early mouse embryos and embryonic stem cells."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      Microarray analysis at early stages of differentiation has identified
      Bptf-dependent gene targets including homeobox transcriptions factors and
      genes essential for the development of ectoderm, mesoderm, and both
      definitive and visceral endoderm.
    explanation: >-
      Microarray profiling during embryonic stem-cell differentiation identifies Bptf-dependent developmental
      genes; this is a cell-culture result.
  - reference: PMID:35604347
    reference_title: "Generation of a mouse model of the neurodevelopmental disorder with dysmorphic facies and distal limb anomalies syndrome."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      RNAseq and pathway analysis identified altered expression of
      fate-determining transcription factors and the biological pathways
      involved in neural development, apoptotic signaling and amino acid
      biosynthesis.
    explanation: >-
      In the disease-specific forebrain Bptf knockout, the transcriptional
      consequence is misexpression of fate-determining transcription factors and
      neural-development/apoptosis pathways.
  - reference: PMID:35604347
    reference_title: "Generation of a mouse model of the neurodevelopmental disorder with dysmorphic facies and distal limb anomalies syndrome."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      Dysregulated genes were enriched for MYC Proto-Oncogene, BHLH
      Transcription Factor (Myc)-binding sites, a known BPTF transcriptional
      cofactor.
    explanation: >-
      Motif enrichment in dysregulated-gene promoters suggests a possible MYC-related mechanism but does
      not measure direct binding or establish a causal cofactor interaction.

  - reference: PMID:18974875
    reference_title: Essential role of chromatin remodeling protein Bptf in early mouse embryos and embryonic stem cells.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      ES cells readily responded to activin-A as monitored by the phosphorylation of Smad2 ... Genes requiring
      Bptf for full activation include Cer1, Gsc and T
    explanation: >-
      Activin-induced Smad2 phosphorylation was preserved, while selected downstream transcriptional responses
      depended on Bptf.
  - reference: PMID:18974875
    reference_title: Essential role of chromatin remodeling protein Bptf in early mouse embryos and embryonic stem cells.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      Reintroduction of BptfFloxed-Neo rescued the induction of mesoderm and endoderm markers during embryoid
      differentiation.
    explanation: >-
      Restoring a functional Bptf allele rescued lineage-marker induction, supporting a Bptf-dependent
      differentiation defect.
- name: Delayed Neural Progenitor Cell-Cycle Exit
  biological_scale: CELLULAR
  mechanism_confidence: PROVISIONAL
  description: >-
    In forebrain-conditional Bptf-null mice, fewer EdU-labeled cells exited the cell cycle over 24 hours.
    A prolonged cycle was inferred from this assay, rather than directly timed. Radial glial abundance,
    S-phase fractions and mitotic-marker counts were largely unchanged, while intermediate progenitor
    abundance was modestly reduced. These complete-loss mouse findings have not been demonstrated in patient
    neural progenitors.
  cell_types:
  - preferred_term: cortical neural progenitor cell
    term:
      id: CL:0011020
      label: neural progenitor cell
  biological_processes:
  - preferred_term: cell cycle
    term:
      id: GO:0007049
      label: cell cycle
    modifier: ABNORMAL
  downstream:
  - target: Cortical Hypoplasia
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: >-
      Altered progenitor differentiation may reduce neuronal output in the conditional-null mouse. The
      study does not show a general cell-cycle arrest.
  evidence:
  - reference: url:https://pmc.ncbi.nlm.nih.gov/articles/PMC9558838/
    reference_title: Generation of a mouse model of the neurodevelopmental disorder with dysmorphic facies and distal limb anomalies syndrome - PMC
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: Taken together, the cortical progenitor cells of the ... cKO mice show no blocks in the cell cycle with similar cell proportions in the S- and M-phase to the control samples. However, fewer cells exited the cell cycle in a 24-h period suggesting that cell cycle length was prolonged, which could account for the slight reduction in IPC number.
    explanation: >-
      Separates the measured cell-cycle exit fraction from the inferred cycle length and preserves negative
      proliferation findings.
- name: Increased Neuronal Apoptosis
  biological_scale: CELLULAR
  mechanism_confidence: PROVISIONAL
  description: >-
    Forebrain Bptf conditional-null mice show increased cleaved-caspase-3 staining chiefly in the intermediate
    zone and cortical plate, with ventricular-zone levels largely unchanged at E15.5. The spatial pattern
    implicates newly postmitotic neurons undergoing differentiation or migration, rather than proving
    generalized progenitor apoptosis. Increased phagocytic microglia accompany postnatal cell death. This
    is a model-derived candidate mechanism for human disease.
  cell_types:
  - preferred_term: differentiating cortical neuron
    term:
      id: CL:0000540
      label: neuron
  biological_processes:
  - preferred_term: apoptotic process
    term:
      id: GO:0006915
      label: apoptotic process
    modifier: INCREASED
  downstream:
  - target: Cortical Hypoplasia
    causal_link_type: DIRECT
  evidence:
  - reference: url:https://pmc.ncbi.nlm.nih.gov/articles/PMC9558838/
    reference_title: Generation of a mouse model of the neurodevelopmental disorder with dysmorphic facies and distal limb anomalies syndrome - PMC
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: We conclude from this data that a high incidence of cell death is a major contributor to the reduction in cortical size and that this occurs as the neurons become postmitotic, initiate their terminal differentiation program, and migrate toward their final laminar position.
    explanation: >-
      Localizes the major cell-death contribution to differentiating neurons in the conditional-null model.
  - reference: PMID:28942966
    reference_title: "Haploinsufficiency of the Chromatin Remodeler BPTF Causes Syndromic Developmental and Speech Delay, Postnatal Microcephaly, and Dysmorphic Features."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      showed a significant increase in cell death in F0 mutants compared to
      controls
    explanation: >-
      Independent, cross-species (zebrafish) confirmation that bptf loss
      increases apoptosis during neurodevelopment.

- name: Impaired Cortical Neuron Fate Specification
  biological_scale: CELLULAR
  mechanism_confidence: PROVISIONAL
  description: >-
    Complete forebrain Bptf loss changes layer-specific neuronal marker expression and distribution. Ctip2-high
    layer V cells are reduced, whereas Ctip2-low cells increase in upper layers; total Ctip2 protein and
    transcript levels are not markedly reduced. Birth-dating does not show fewer EdU/Ctip2-colabeled cells,
    supporting impaired regulation and maturation rather than simply absent production of this neuronal
    class. These findings do not establish cortical mislamination in human heterozygous disease.
  cell_types:
  - preferred_term: cortical projection neuron
    term:
      id: CL:0000540
      label: neuron
  biological_processes:
  - preferred_term: cerebral cortex neuron differentiation
    term:
      id: GO:0021895
      label: cerebral cortex neuron differentiation
    modifier: DECREASED
  downstream:
  - target: Neurodevelopmental Impairment
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: >-
      Altered cortical neuronal identity may affect circuit function, but cognition and seizure physiology
      were not characterized in this mouse study.
  evidence:
  - reference: url:https://pmc.ncbi.nlm.nih.gov/articles/PMC9558838/
    reference_title: Generation of a mouse model of the neurodevelopmental disorder with dysmorphic facies and distal limb anomalies syndrome - PMC
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: Immunoblots suggested the overall levels of Ctip2 were not markedly different than in the control extracts
    explanation: >-
      Preserves the negative bulk-protein result despite altered layer-specific Ctip2 staining.
  - reference: url:https://pmc.ncbi.nlm.nih.gov/articles/PMC9558838/
    reference_title: Generation of a mouse model of the neurodevelopmental disorder with dysmorphic facies and distal limb anomalies syndrome - PMC
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: suggesting that these cells are specified but have impaired Ctip2 regulation that alters lamination and terminal expression levels.
    explanation: >-
      Interpretation of the birth-dating experiment; the neuron class is not simply absent at birth.
- name: Cortical Hypoplasia
  biological_scale: TISSUE
  mechanism_confidence: PROVISIONAL
  description: >-
    Forebrain-conditional Bptf-null mice have reduced cortical size from birth. Gross anatomy did not
    progressively worsen with age. This provides a developmental model for reduced brain growth, but most
    imaged individuals in the human expansion cohort had normal MRI and the remaining changes were heterogeneous.
    Mouse cortical hypoplasia cannot be equated with every human MRI abnormality or with a demonstrated
    cause of human epilepsy.
  cell_types:
  - preferred_term: cortical projection neuron
    term:
      id: CL:0000540
      label: neuron
  biological_processes:
  - preferred_term: cerebral cortex development
    term:
      id: GO:0021987
      label: cerebral cortex development
    modifier: ABNORMAL
  locations:
  - preferred_term: cerebral cortex
    term:
      id: UBERON:0000956
      label: cerebral cortex
  downstream:
  - target: Reduced Brain Growth
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: >-
      The conditional-null cortical phenotype provides a candidate route to human microcephaly; the human
      cellular substrate and dosage relationship remain unresolved.
  evidence:
  - reference: PMID:35604347
    reference_title: "Generation of a mouse model of the neurodevelopmental disorder with dysmorphic facies and distal limb anomalies syndrome."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      The Bptf cKO mice were born in normal Mendelian ratios, survived to
      adulthood but were smaller in size with severe cortical hypoplasia.
    explanation: >-
      Establishes cortical hypoplasia with reduced body size as the tissue-level
      phenotype of forebrain Bptf loss.
  - reference: url:https://pmc.ncbi.nlm.nih.gov/articles/PMC9558838/
    reference_title: Generation of a mouse model of the neurodevelopmental disorder with dysmorphic facies and distal limb anomalies syndrome - PMC
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: The gross morphology of the hypoplastic forebrain remained identical to the P12 mice as the mice aged
    explanation: >-
      Supports a developmental, grossly nonprogressive anatomical phenotype in the model.
- name: Disrupted Craniofacial and Limb Patterning
  biological_scale: TISSUE
  mechanism_confidence: PROVISIONAL
  description: >-
    Zebrafish bptf disruption increases the ceratohyal cartilage angle, supporting a role in craniofacial
    development. The specific cellular lineage and molecular route to human facial or distal limb findings
    have not been demonstrated. A shared developmental-patterning disturbance is proposed, rather than
    an established migratory neural-crest defect or a measured human HOX-expression mechanism.
  biological_processes:
  - preferred_term: embryonic skeletal system morphogenesis
    term:
      id: GO:0048704
      label: embryonic skeletal system morphogenesis
    modifier: ABNORMAL
  - preferred_term: embryonic limb morphogenesis
    term:
      id: GO:0030326
      label: embryonic limb morphogenesis
    modifier: ABNORMAL
  downstream:
  - target: Dysmorphic Facial Features
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: >-
      A candidate developmental connection based on co-occurring human findings and experimental craniofacial
      abnormalities; the human causal route is unproven.
  - target: Distal Limb Anomalies
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: >-
      A candidate developmental connection based on co-occurring human findings and experimental craniofacial
      abnormalities; the human causal route is unproven.
  evidence:
  - reference: PMID:28942966
    reference_title: "Haploinsufficiency of the Chromatin Remodeler BPTF Causes Syndromic Developmental and Speech Delay, Postnatal Microcephaly, and Dysmorphic Features."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      we observed a substantial increase of the ceratohyal angle of the
      craniofacial skeleton in bptf F0 mutants, indicating abnormal craniofacial
      patterning
    explanation: >-
      Experimental demonstration that bptf loss disrupts craniofacial
      patterning, the model-organism correlate of the human dysmorphic facies.
  - reference: PMID:16728976
    reference_title: "A PHD finger of NURF couples histone H3 lysine 4 trimethylation with chromatin remodelling."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      NURF-mediated ATP-dependent chromatin remodelling is directly coupled to
      H3K4 trimethylation to maintain Hox gene expression patterns during
      development
    explanation: >-
      Supplies the HOX-patterning link that makes limb and craniofacial
      patterning a plausible consequence of BPTF loss; indirect with respect to
      the human limb findings, whose specific molecular route remains unproven.
  - reference: PMID:33522091
    reference_title: "Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The mechanism for these abnormalities is less clear, though it is presumed
      that they are also derived from abnormal signaling during embryogenesis
      similar to the distal limb defects commonly described in these patients.
    explanation: >-
      The disease literature itself states the developmental-patterning
      inference is presumptive, which is why this node is PROVISIONAL.

- name: Reduced Brain Growth
  biological_scale: ORGANISM
  mechanism_confidence: PROVISIONAL
  description: >-
    Microcephaly in BPTF-related disease can be congenital or emerge after birth. Reduced larval head
    size after zebrafish bptf disruption and cortical hypoplasia in conditional-null mice support a developmental
    contribution, but the exact cellular route in human heterozygous disease is unresolved. Microcephaly
    and neurodevelopmental impairment may share upstream causes; reduced head size does not itself establish
    the cause of cognitive impairment.
  downstream:
  - target: Microcephaly
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: >-
      Reduced brain growth provides a candidate basis for small head circumference across congenital
      and postnatal presentations; the precise human cellular mechanism remains unresolved.
  - target: Postnatal Microcephaly
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: >-
      Reduced postnatal brain growth is a plausible basis for secondary microcephaly documented in the
      founding cohort. This timing-specific phenotype is a subset of the general microcephaly finding.
  evidence:
  - reference: PMID:28942966
    reference_title: "Haploinsufficiency of the Chromatin Remodeler BPTF Causes Syndromic Developmental and Speech Delay, Postnatal Microcephaly, and Dysmorphic Features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      who manifest variable degrees of developmental delay/intellectual
      disability (10/10), speech delay (10/10), postnatal microcephaly (7/9),
      and dysmorphic features (9/10)
    explanation: >-
      Establishes the postnatal (rather than congenital) timing of the
      microcephaly in the founding cohort.
  - reference: PMID:28942966
    reference_title: "Haploinsufficiency of the Chromatin Remodeler BPTF Causes Syndromic Developmental and Speech Delay, Postnatal Microcephaly, and Dysmorphic Features."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      Using CRISPR-Cas9 genome editing of bptf in zebrafish to induce a loss of
      gene function, we observed a significant reduction in head size of F0
      mutants compared to control larvae.
    explanation: >-
      Model-organism recapitulation of reduced head size on bptf loss.
- name: Somatic Growth Impairment
  biological_scale: ORGANISM
  mechanism_confidence: PROVISIONAL
  description: >-
    Short stature, low weight and feeding difficulty occur variably in human BPTF-related disease. Growth
    hormone deficiency was documented in two treated boys, but is not established as the explanation for
    all growth impairment. The connection between chromatin dysregulation and somatic growth remains uncertain
    and is separate from the brain-growth mechanism.
  downstream:
  - target: Short Stature
    causal_link_type: DIRECT
  - target: Poor Weight Gain and Malnutrition
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: >-
      Feeding difficulty and other factors may contribute; low weight alone does not establish growth
      velocity or a single causal pathway.
  - target: Decreased Body Weight
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: >-
      Somatic growth impairment can present as low weight for age. The cohort measurements establish
      this association without identifying the relative contributions of feeding or endocrine factors.
  evidence:
  - reference: PMID:33522091
    reference_title: "Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      At the time of their most recent clinical assessment, 5/20 (25%)
      individuals exhibited short stature for age and 10/19 (53%) individuals
      had decreased weight for age
    explanation: >-
      Quantifies the somatic growth restriction that accompanies the
      microcephaly.

- name: Neurodevelopmental Impairment
  biological_scale: ORGANISM
  mechanism_confidence: ESTABLISHED
  description: >-
    Human BPTF-related disease includes developmental delay, intellectual disability, speech/language
    delay, motor delay and hypotonia with variable expressivity. Some individuals function independently
    as adults. Developmental delay commonly precedes seizures, but this does not prove a specific cortical
    lesion or exclude additional developmental effects from epilepsy.
  downstream:
  - target: Global Developmental Delay
    causal_link_type: DIRECT
    description: >-
      The impairment presents first as delayed attainment of milestones across
      all developmental domains.
  - target: Intellectual Disability
    causal_link_type: DIRECT
    description: >-
      Intellectual disability occurs in some affected individuals; global developmental delay does not
      invariably imply later intellectual disability.
  - target: Delayed Speech and Language Development
    causal_link_type: DIRECT
    description: >-
      Speech and language are disproportionately affected relative to other
      domains, making this the most consistent single manifestation.
  - target: Motor Delay
    causal_link_type: DIRECT
    description: >-
      Gross and fine motor milestones are delayed alongside the cognitive and
      language domains.
  - target: Hypotonia
    causal_link_type: DIRECT
    description: >-
      Hypotonia accompanies the neurodevelopmental phenotype; its specific causal route is unresolved.
  evidence:
  - reference: PMID:33522091
    reference_title: "Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Common features included DD and/or ID (23/26, 88%), speech delay (22/26,
      85%), head circumference less than the third percentile for age (11/26,
      42%), motor delay (18/26, 69%), hypotonia (10/26, 38%), and dysmorphic
      features (20/26, 77%).
    explanation: >-
      Quantifies the organism-level clinical output across the largest
      single-study cohort.
  - reference: PMID:38936258
    reference_title: "Epilepsy as a Novel Phenotype of BPTF-Related Disorders."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      developmental delay preceding seizure onset
    explanation: >-
      Reports temporal ordering of developmental delay and seizures without establishing a cortical lesion
      or a causal relationship.

phenotypes:
- category: Neurologic
  name: Global Developmental Delay
  phenotype_term:
    preferred_term: Global developmental delay
    term:
      id: HP:0001263
      label: Global developmental delay
  description: >-
    Delayed attainment of developmental milestones across domains, with variable later cognitive outcomes.
    Severity ranges from substantial impairment requiring support to mild learning difficulties compatible
    with employment and independent adult function; developmental delay does not invariably establish
    intellectual disability.
  notes: >-
    The 2021 cohort reported developmental delay and/or intellectual disability jointly in 23/26 individuals.
    This composite does not provide a separate global-developmental-delay frequency. The 2017 cohort also
    reported the two findings jointly.
  evidence:
  - reference: PMID:33522091
    reference_title: "Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Common features included DD and/or ID (23/26, 88%), speech delay (22/26,
      85%), head circumference less than the third percentile for age (11/26,
      42%), motor delay (18/26, 69%), hypotonia (10/26, 38%), and dysmorphic
      features (20/26, 77%).
    explanation: >-
      Supports the combined developmental-delay/intellectual-disability phenotype; it does not distinguish
      the frequency of each component.
  - reference: PMID:28942966
    reference_title: "Haploinsufficiency of the Chromatin Remodeler BPTF Causes Syndromic Developmental and Speech Delay, Postnatal Microcephaly, and Dysmorphic Features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      who manifest variable degrees of developmental delay/intellectual
      disability (10/10), speech delay (10/10), postnatal microcephaly (7/9),
      and dysmorphic features (9/10)
    explanation: >-
      Founding cohort: developmental delay/intellectual disability in all ten
      individuals.

- category: Neurologic
  name: Intellectual Disability
  phenotype_term:
    preferred_term: Intellectual disability
    term:
      id: HP:0001249
      label: Intellectual disability
  description: >-
    Intellectual disability varies in severity. Some individuals have mild learning difficulties and independent
    adult function; developmental delay in a young child does not by itself establish intellectual disability.
    A proposed association with distal limb abnormalities in a four-person series remains uncertain, particularly
    because three participants carried missense variants classified as VUS.
  notes: >-
    The 23/26 composite developmental delay and/or intellectual disability count does not estimate intellectual
    disability separately.
  evidence:
  - reference: PMID:33522091
    reference_title: "Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Common features included DD and/or ID (23/26, 88%), speech delay (22/26,
      85%), head circumference less than the third percentile for age (11/26,
      42%), motor delay (18/26, 69%), hypotonia (10/26, 38%), and dysmorphic
      features (20/26, 77%).
    explanation: >-
      Provides the composite DD/ID fraction.
  - reference: PMID:40415676
    reference_title: "Effects of the Missense Variants on Complete Phenotype and Splicing Variant on Severe Growth Retardation in the BPTF Gene."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      We suggest that distal limb abnormalities associated with the BPTF gene
      may accompany a more severe diagnosis of intellectual disability.
    explanation: >-
      An exploratory severity hypothesis from four individuals, three with missense VUS; it is not an
      established prognostic association.

- category: Neurologic
  name: Delayed Speech and Language Development
  frequency: VERY_FREQUENT
  phenotype_term:
    preferred_term: Delayed speech and language development
    term:
      id: HP:0000750
      label: Delayed speech and language development
  description: >-
    Speech and language delay is a cardinal and disproportionately prominent
    feature of NEDDFL, reported in every individual in the founding cohort and
    in the great majority of all reported individuals.
  notes: >-
    Frequency band from PMID:33522091 (speech delay 22/26, 85% ->
    VERY_FREQUENT); the founding cohort reported 10/10 and the pooled 38-case
    table in PMID:36153657 gives 33/38 (87%).
  evidence:
  - reference: PMID:28942966
    reference_title: "Haploinsufficiency of the Chromatin Remodeler BPTF Causes Syndromic Developmental and Speech Delay, Postnatal Microcephaly, and Dysmorphic Features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      who manifest variable degrees of developmental delay/intellectual
      disability (10/10), speech delay (10/10), postnatal microcephaly (7/9),
      and dysmorphic features (9/10)
    explanation: >-
      Speech delay in 10/10 of the founding cohort.
  - reference: PMID:33522091
    reference_title: "Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Common features included DD and/or ID (23/26, 88%), speech delay (22/26,
      85%), head circumference less than the third percentile for age (11/26,
      42%), motor delay (18/26, 69%), hypotonia (10/26, 38%), and dysmorphic
      features (20/26, 77%).
    explanation: >-
      Supplies the 85% denominator for the VERY_FREQUENT band.

- category: Neurologic
  name: Motor Delay
  frequency: FREQUENT
  phenotype_term:
    preferred_term: Motor delay
    term:
      id: HP:0001270
      label: Motor delay
  description: >-
    Delayed acquisition of gross and fine motor milestones.
  notes: >-
    Frequency band from the original 2021 cohort: motor delay in 18/26 (69%), corresponding to FREQUENT.
    The later pooled table prints 26/28 as 68%, an arithmetic inconsistency, and is not used for this
    frequency.
  evidence:
  - reference: PMID:33522091
    reference_title: "Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Common features included DD and/or ID (23/26, 88%), speech delay (22/26,
      85%), head circumference less than the third percentile for age (11/26,
      42%), motor delay (18/26, 69%), hypotonia (10/26, 38%), and dysmorphic
      features (20/26, 77%).
    explanation: >-
      Motor delay in 18/26 (69%) of the expansion cohort, mapping to FREQUENT.

- category: Neurologic
  name: Hypotonia
  frequency: FREQUENT
  phenotype_term:
    preferred_term: Hypotonia
    term:
      id: HP:0001252
      label: Hypotonia
  description: >-
    Reduced muscle tone, typically appreciated in infancy and contributing to
    feeding difficulty and motor delay.
  notes: >-
    Frequency band from PMID:33522091 (hypotonia 10/26, 38% -> FREQUENT); the
    pooled table in PMID:36153657 reports 15/38 (39%), concordant.
  evidence:
  - reference: PMID:33522091
    reference_title: "Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Common features included DD and/or ID (23/26, 88%), speech delay (22/26,
      85%), head circumference less than the third percentile for age (11/26,
      42%), motor delay (18/26, 69%), hypotonia (10/26, 38%), and dysmorphic
      features (20/26, 77%).
    explanation: >-
      Hypotonia in 10/26 (38%), mapping to FREQUENT.

- category: Neurologic
  name: Postnatal Microcephaly
  phenotype_term:
    preferred_term: Secondary microcephaly
    term:
      id: HP:0005484
      label: Secondary microcephaly
    onset:
      onset_category: INFANTILE
  description: >-
    Secondary microcephaly was reported in 7/9 assessed individuals in the founding cohort. Congenital
    microcephaly also occurs. The expansion cohort reported low head circumference in 4/10 at birth and
    12/20 at last assessment, but these different denominators do not identify how many individuals developed
    microcephaly after birth.
  notes: >-
    The 2021 overall microcephaly counts include individuals small-headed at birth and therefore cannot
    supply a frequency for secondary microcephaly.
  evidence:
  - reference: PMID:28942966
    reference_title: "Haploinsufficiency of the Chromatin Remodeler BPTF Causes Syndromic Developmental and Speech Delay, Postnatal Microcephaly, and Dysmorphic Features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      who manifest variable degrees of developmental delay/intellectual
      disability (10/10), speech delay (10/10), postnatal microcephaly (7/9),
      and dysmorphic features (9/10)
    explanation: >-
      Names the microcephaly as postnatal and reports it in 7/9 assessed
      individuals in the founding cohort.
  - reference: PMID:33522091
    reference_title: "Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      12/20 (60%) individuals demonstrated a head circumference less than the
      third percentile for age
    explanation: >-
      Quantifies microcephaly at last clinical assessment in the expansion
      cohort.

- category: Neurologic
  name: Epilepsy
  frequency: OCCASIONAL
  phenotype_term:
    preferred_term: Seizure
    term:
      id: HP:0001250
      label: Seizure
    onset:
      onset_category: CHILDHOOD
  description: >-
    Epilepsy has been reported with onset from 10 months to 7 years (median 4 years) in an electroclinically
    ascertained series of 11 individuals. Eight had epilepsy, one had a single unprovoked seizure and
    two had interictal epileptiform discharges only. The EEG background was well organized, with generalized
    interictal abnormalities in about half. Developmental delay preceded seizures; this timing does not
    establish a cortical lamination defect or exclude later effects of seizures on development. Drug resistance
    was reported as 27% in the selected series, not as a population rate.
  notes: >-
    The 2024 authors report epilepsy in 19% of known subjects; this is a literature-based proportion,
    distinct from the selected eleven-person electroclinical series. The 2021 cohort includes four individuals
    with clinical seizures and two with EEG abnormalities only, rather than six confirmed epilepsy cases.
  evidence:
  - reference: PMID:38936258
    reference_title: "Epilepsy as a Novel Phenotype of BPTF-Related Disorders."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Early-childhood-onset epilepsy occurs in 19% of subjects, all presenting
      with a well-organized EEG background associated with generalized
      interictal epileptiform abnormalities in half of these cases. Drug
      resistance is rare.
    explanation: >-
      Supplies both the 19% frequency underpinning the OCCASIONAL band and the
      electroclinical characterization.
  - reference: PMID:33522091
    reference_title: "Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Here, however, we identified six individuals with a history of clinical
      seizures and/or abnormal electroencephalograms (manuscript in
      preparation).
    explanation: >-
      Independent cohort confirming seizures as part of the NEDDFL spectrum and
      noting they were previously unreported.

- category: Neurologic
  name: EEG Abnormality
  phenotype_term:
    preferred_term: EEG abnormality
    term:
      id: HP:0002353
      label: EEG abnormality
  description: >-
    Interictal epileptiform discharges may be present without clinical seizures.
    Two of eleven individuals in the dedicated epilepsy series had IEDs only.
  notes: >-
    Frequency omitted: the denominator (11 individuals) is an
    epilepsy-ascertained series, not an unselected NEDDFL cohort, so a
    population band cannot be derived.
  evidence:
  - reference: PMID:38936258
    reference_title: "Epilepsy as a Novel Phenotype of BPTF-Related Disorders."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Eight individuals had epilepsy, one had a single unprovoked seizure, and
      two showed IEDs only.
    explanation: >-
      Documents isolated interictal epileptiform discharges as a distinct
      electrographic finding.

- category: Neurologic
  name: Structural Brain Abnormality
  frequency: FREQUENT
  phenotype_term:
    preferred_term: Abnormal brain morphology
    term:
      id: HP:0012443
      label: Abnormal brain morphology
    severity: MILD
    coarse_binding_basis: SOURCE_UNSPECIFIED
  description: >-
    In the 2021 cohort, eight of thirteen brain MRI studies were normal and five showed mild structural
    abnormalities. The aggregate MRI summary does not identify a characteristic malformation. A normal
    MRI does not exclude BPTF-related disease.
  notes: >-
    The FREQUENT band refers to five of thirteen imaged individuals in the 2021 cohort, not a population
    prevalence. The broad binding retains the unspecified structural-abnormality category used in the
    quoted cohort summary; individual MRI findings are heterogeneous. The later pooled table is not used
    to infer a syndrome-wide imaging frequency.
  evidence:
  - reference: PMID:33522091
    reference_title: "Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Magnetic resonance imaging (MRI) studies were obtained for 13/26 patients
      and were found to be normal in 8/13 cases. The remaining five studies
      demonstrated mild structural abnormalities only
    explanation: >-
      Provides the 5/13 abnormal MRI fraction and characterizes changes as mild within this cohort, without
      establishing a uniform human cortical lesion.

- category: Craniofacial
  name: Dysmorphic Facial Features
  frequency: VERY_FREQUENT
  phenotype_term:
    preferred_term: Abnormal facial shape
    term:
      id: HP:0001999
      label: Abnormal facial shape
    severity: MILD
  description: >-
    A mild but recognizable facial gestalt. The most consistently reported
    elements are nasal: prominent nasal tip, bulbous nasal tip, and prominent
    nasal bridge, together with a pointed chin.
  notes: >-
    Frequency band from PMID:33522091, in which mild dysmorphic features were
    present in all 20 individuals with available dysmorphology assessment
    (20/20 -> VERY_FREQUENT); the same paper reports 20/26 (77%) over the whole
    cohort including individuals not assessed, and the founding cohort reported
    9/10.
  evidence:
  - reference: PMID:33522091
    reference_title: "Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      mild dysmorphic features were identified in all available subjects (20/20
      individuals)
    explanation: >-
      Supplies the 20/20 denominator for the VERY_FREQUENT band and establishes
      that the dysmorphism is mild.
  - reference: PMID:28942966
    reference_title: "Haploinsufficiency of the Chromatin Remodeler BPTF Causes Syndromic Developmental and Speech Delay, Postnatal Microcephaly, and Dysmorphic Features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      who manifest variable degrees of developmental delay/intellectual
      disability (10/10), speech delay (10/10), postnatal microcephaly (7/9),
      and dysmorphic features (9/10)
    explanation: >-
      Dysmorphic features in 9/10 of the founding cohort.

- category: Craniofacial
  name: Bulbous Nasal Tip
  phenotype_term:
    preferred_term: Bulbous nose
    term:
      id: HP:0000414
      label: Bulbous nose
  description: >-
    A rounded, broadened nasal tip, one of the recurrent nasal features of the
    NEDDFL facial gestalt.
  notes: >-
    The 2021 report counted nasal abnormalities collectively in 9/20 assessed individuals. This includes
    prominent nasal tip, bulbous nasal tip and prominent nasal bridge and does not establish the frequency
    of this individual feature.
  evidence:
  - reference: PMID:33522091
    reference_title: "Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Commonly identified features included a number of nasal abnormalities
      (prominent nasal tip, bulbous nasal tip, and prominent nasal bridge) in
      9/20 (45%) individuals
    explanation: >-
      Names bulbous nasal tip among the recurrent nasal features and supplies
      the 45% group denominator.

- category: Craniofacial
  name: Prominent Nasal Bridge
  phenotype_term:
    preferred_term: Prominent nasal bridge
    term:
      id: HP:0000426
      label: Prominent nasal bridge
  description: >-
    A forward-projecting nasal bridge contributing to the facial gestalt.
  notes: >-
    The 2021 report counted nasal abnormalities collectively in 9/20 assessed individuals. This includes
    prominent nasal tip, bulbous nasal tip and prominent nasal bridge and does not establish the frequency
    of this individual feature.
  evidence:
  - reference: PMID:33522091
    reference_title: "Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Commonly identified features included a number of nasal abnormalities
      (prominent nasal tip, bulbous nasal tip, and prominent nasal bridge) in
      9/20 (45%) individuals
    explanation: >-
      Names prominent nasal bridge among the recurrent nasal features.

- category: Craniofacial
  name: Pointed Chin
  phenotype_term:
    preferred_term: Pointed chin
    term:
      id: HP:0000307
      label: Pointed chin
  description: >-
    A narrow, tapering chin, noted across the published clinical photographs as
    a recurrent element of the facial gestalt.
  notes: >-
    Frequency omitted: PMID:33522091 documents pointed chin only in the
    photograph legend, without a numerator/denominator, so no band can be
    derived.
  evidence:
  - reference: PMID:33522091
    reference_title: "Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      bulbous nasal tip (a, d, h, k, m, n), and pointed chin (a, c, d, e, f, i,
      k, m, n)
    explanation: >-
      Clinical photograph annotation documenting pointed chin across multiple
      individuals.

- category: Skeletal
  name: Distal Limb Anomalies
  phenotype_term:
    preferred_term: Distal limb anomalies (hands and feet)
    term:
      id: HP:0011297
      label: Abnormal digit morphology
  description: >-
    Mild anomalies of the hands and feet are one of the two features that name
    the syndrome. The recurrent findings are cutaneous 2-3 toe syndactyly,
    sandal gap, and fifth-finger clinodactyly; a subset also has limb-length
    discrepancy.
  notes: >-
    Skeletal abnormalities occurred in 13/26 individuals in the 2021 cohort, but that count also includes
    scoliosis, kyphosis and delayed bone age. It cannot estimate distal limb or digit abnormalities specifically.
  evidence:
  - reference: PMID:33522091
    reference_title: "Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      we also identified the presence of skeletal abnormalities in 50% (13/26)
      of individuals
    explanation: >-
      Describes the broader skeletal group, including axial abnormalities; the 13/26 count is not a digit-specific
      frequency.
  - reference: PMID:33522091
    reference_title: "Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      In addition to DDs, microcephaly, and distal limb defects, our cohort
      exhibited an increased frequency of ophthalmologic abnormalities, poor
      weight gain/poor feeding, and cutaneous syndactyly of the toes.
    explanation: >-
      Names cutaneous syndactyly of the toes as a recurrent distal limb finding.
  - reference: PMID:40415676
    reference_title: "Effects of the Missense Variants on Complete Phenotype and Splicing Variant on Severe Growth Retardation in the BPTF Gene."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Additionally, all four of our cases in this study had distal limb
      abnormalities such as syndactyly and clinodactyly that accompany severe
      intellectual disability.
    explanation: >-
      Describes syndactyly and clinodactyly in four individuals, but three carry missense VUS and cannot
      be used as independent genetically confirmed cases for a frequency estimate.

- category: Skeletal
  name: Sandal Gap
  phenotype_term:
    preferred_term: Sandal gap
    term:
      id: HP:0001852
      label: Sandal gap
  description: >-
    An increased gap between the first and second toes, reported in five
    individuals in the phenotypic expansion cohort.
  notes: >-
    Frequency omitted: PMID:33522091 reports a raw count of five individuals
    within the subgroup of 13 with skeletal abnormalities, without a whole-cohort
    denominator.
  evidence:
  - reference: PMID:33522091
    reference_title: "Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Note the presence of fifth finger clinodactyly (d), sandal gap deformity
      (i, k) and cutaneous syndactyly (j, k)
    explanation: >-
      Clinical photograph annotation documenting sandal gap in the cohort.

- category: Skeletal
  name: Fifth-Finger Clinodactyly
  phenotype_term:
    preferred_term: Clinodactyly of the 5th finger
    term:
      id: HP:0004209
      label: Clinodactyly of the 5th finger
  description: >-
    Radial curvature of the fifth finger, part of the mild hand anomaly
    component of the syndrome.
  notes: >-
    Frequency omitted: documented in PMID:33522091 only as a photograph
    annotation without a denominator, and in PMID:40415676 in all four cases of
    a small ascertained series.
  evidence:
  - reference: PMID:33522091
    reference_title: "Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Note the presence of fifth finger clinodactyly (d), sandal gap deformity
      (i, k) and cutaneous syndactyly (j, k)
    explanation: >-
      Clinical photograph annotation documenting fifth-finger clinodactyly.

- category: Skeletal
  name: Scoliosis
  frequency: OCCASIONAL
  phenotype_term:
    preferred_term: Scoliosis
    term:
      id: HP:0002650
      label: Scoliosis
  description: >-
    Lateral curvature of the spine, reported in five of the 13 individuals with
    skeletal abnormalities in the phenotypic expansion cohort. Careful
    examination and monitoring for scoliosis is recommended in NEDDFL.
  notes: >-
    Band derived conservatively: PMID:33522091 reports 5/13 (38.5%) of the
    skeletal-abnormality subgroup, which corresponds to 5/26 (19%) of the whole
    cohort. The whole-cohort denominator is the appropriate one for a
    disease-level frequency, giving OCCASIONAL (5-29%).
  evidence:
  - reference: PMID:33522091
    reference_title: "Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      These included the presence of scoliosis in five individuals (5/13,
      38.5%)
    explanation: >-
      Supplies the scoliosis count within the skeletal-abnormality subgroup of
      the 26-individual cohort.

- category: Skeletal
  name: Delayed Bone Age
  phenotype_term:
    preferred_term: Delayed skeletal maturation
    term:
      id: HP:0002750
      label: Delayed skeletal maturation
  description: >-
    Bone age delayed relative to chronological age, reported in two individuals
    in the phenotypic expansion cohort.
  notes: >-
    Frequency omitted: only two individuals, reported as a raw count within the
    skeletal-abnormality subgroup of PMID:33522091.
  evidence:
  - reference: PMID:33522091
    reference_title: "Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      and delayed bone age in two individuals (2/13, 15%)
    explanation: >-
      Documents delayed skeletal maturation in the cohort.

- category: Growth
  name: Short Stature
  frequency: FREQUENT
  phenotype_term:
    preferred_term: Short stature
    term:
      id: HP:0004322
      label: Short stature
  description: >-
    Height below the third percentile for age. A subset of individuals has
    documented growth hormone deficiency on stimulation testing and responds to
    recombinant human growth hormone.
  notes: >-
    Frequency band from PMID:36153657, which states in its abstract that about
    35% of patients have short stature -> FREQUENT. PMID:33522091 independently
    reports 5/20 (25%) at last assessment, which would map to OCCASIONAL; the
    larger pooled denominator behind the 35% figure is preferred, and the
    discrepancy is recorded here rather than hidden.
  evidence:
  - reference: PMID:36153657
    reference_title: "The effect of growth hormone treatment in children with novel BPTF gene variants: A report of two cases and literature review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      About 35% of the patients had short stature, but there had no reports
      published on the treatment.
    explanation: >-
      Explicit 35% short-stature frequency supporting the FREQUENT band.
  - reference: PMID:33522091
    reference_title: "Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      At the time of their most recent clinical assessment, 5/20 (25%)
      individuals exhibited short stature for age and 10/19 (53%) individuals
      had decreased weight for age
    explanation: >-
      The independent cohort estimate of 25% supports the short-stature association but falls in a
      different frequency band from the later pooled estimate of 35%.

- category: Growth
  name: Poor Weight Gain and Malnutrition
  phenotype_term:
    preferred_term: Failure to thrive
    term:
      id: HP:0001508
      label: Failure to thrive
  description: >-
    Poor weight gain with moderate to severe malnutrition is common, frequently
    beginning in infancy alongside feeding difficulty.
  notes: >-
    The expansion cohort reported weight below the third percentile in 10/19 assessed individuals. A single
    low-weight measurement is not equivalent to poor weight gain or failure to thrive, so this proportion
    is not used as a frequency for this entry.
  evidence:
  - reference: PMID:33522091
    reference_title: "Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      At the time of their most recent clinical assessment, 5/20 (25%)
      individuals exhibited short stature for age and 10/19 (53%) individuals
      had decreased weight for age
    explanation: >-
      Documents low weight for age; this supports the growth phenotype but does not by itself establish
      the rate of weight gain.

- category: Gastrointestinal
  name: Feeding Difficulties
  phenotype_term:
    preferred_term: Feeding difficulties
    term:
      id: HP:0011968
      label: Feeding difficulties
  description: >-
    Poor feeding, contributing to the poor weight gain, and identified as an
    expanded feature of the syndrome.
  notes: >-
    Frequency omitted: PMID:33522091 reports poor feeding qualitatively as an
    increased-frequency finding without a numerator/denominator.
  evidence:
  - reference: PMID:33522091
    reference_title: "Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      In addition to DDs, microcephaly, and distal limb defects, our cohort
      exhibited an increased frequency of ophthalmologic abnormalities, poor
      weight gain/poor feeding, and cutaneous syndactyly of the toes.
    explanation: >-
      Names poor feeding as an expanded feature of NEDDFL.

- category: Gastrointestinal
  name: Cyclical Vomiting Syndrome
  phenotype_term:
    preferred_term: Episodic vomiting
    term:
      id: HP:0002572
      label: Episodic vomiting
    temporality: RECURRENT
  description: >-
    Stereotyped, recurrent episodes of vomiting, typically lasting under an
    hour, with a median onset around age 3 years and common triggers of poor
    sleep and fever. Formally diagnosed as cyclical vomiting syndrome by ICHD-3
    criteria in 20% of one prospectively questioned series, with a further 27%
    meeting at least three of the criteria. Episodes are a substantial source of
    family burden.
  notes: >-
    Three of 15 individuals met full ICHD-3 CVS criteria, and four additional individuals met at least
    three criteria. The study recruited families with or without gastrointestinal symptoms. The 20% CVS
    proportion is from this small questionnaire cohort and is not the frequency of all episodic vomiting.
  evidence:
  - reference: PMID:40614698
    reference_title: "Cyclical Vomiting Syndrome in Individuals With BPTF Haploinsufficiency."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      We enrolled 15 individuals with likely pathogenic/pathogenic BPTF variants
      (median age: 8.8 years). Three individuals (20%) were diagnosed with CVS,
      and an additional four individuals (26.7%) met at least three of the
      ICHD-3 criteria for CVS.
    explanation: >-
      Distinguishes the three confirmed CVS cases from four additional individuals with recurrent vomiting
      meeting partial criteria.
  - reference: PMID:40614698
    reference_title: "Cyclical Vomiting Syndrome in Individuals With BPTF Haploinsufficiency."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      This study broadens the syndromic phenotype associated with BPTF
      haploinsufficiency, highlighting CVS as a core feature.
    explanation: >-
      The authors propose CVS as part of the syndrome; the small observational series establishes an association
      rather than proving causality for each episode.

- category: Ophthalmologic
  name: Exotropia
  phenotype_term:
    preferred_term: Exotropia
    term:
      id: HP:0000577
      label: Exotropia
  description: >-
    Divergent strabismus, the most frequently reported single ophthalmologic
    finding in NEDDFL (six individuals in the phenotypic expansion cohort).
  notes: >-
    The 2021 report described 13 individuals with ophthalmologic findings overall, including six with
    exotropia, two with other strabismus and three with confirmed myopia. These categories may overlap
    and do not supply a uniformly examined denominator for each specific phenotype.
  evidence:
  - reference: PMID:33522091
    reference_title: "Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Interestingly, 13 individuals demonstrated mild ophthalmologic
      abnormalities. These included the finding of exotropia in six individuals,
      strabismus in two individuals, and confirmed myopia in three individuals.
    explanation: >-
      Documents exotropia as the most common specific ophthalmologic finding.

- category: Ophthalmologic
  name: Myopia
  phenotype_term:
    preferred_term: Myopia
    term:
      id: HP:0000545
      label: Myopia
  description: >-
    Confirmed myopia in three individuals in the phenotypic expansion cohort.
  notes: >-
    Frequency omitted for the same denominator ambiguity as exotropia.
  evidence:
  - reference: PMID:33522091
    reference_title: "Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Interestingly, 13 individuals demonstrated mild ophthalmologic
      abnormalities. These included the finding of exotropia in six individuals,
      strabismus in two individuals, and confirmed myopia in three individuals.
    explanation: >-
      Documents confirmed myopia in the cohort.

- name: Cutaneous Toe Syndactyly
  category: Musculoskeletal
  phenotype_term:
    preferred_term: Cutaneous syndactyly of toes
    term:
      id: HP:0010621
      label: Cutaneous syndactyly of toes
  description: >-
    Soft-tissue syndactyly, often of toes 2 and 3, occurs in the clinical spectrum. Attribution is uncertain
    in at least one reported individual whose family history suggested a separate dominant syndactyly
    trait.
  evidence:
  - reference: PMID:33522091
    reference_title: Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Metopic ridge, brachycephaly, mild micrognathia, synophrys, apparently long tongue, cutis marmorata;
      square finger tips, moderate soft tissue syndactyly of toes 2 and 3, broad great toes and thumbs,
      wide sandal gap deformities
    explanation: >-
      Table 2 documents soft-tissue toe syndactyly in patient 7; the separate familial explanation for
      patient 18 prevents assuming that every syndactyly observation is caused by BPTF.
- name: Broad Great Toes
  category: Musculoskeletal
  phenotype_term:
    preferred_term: Broad hallux
    term:
      id: HP:0010055
      label: Broad hallux
  description: >-
    Broad great toes or halluces are recurrent distal-limb findings.
  evidence:
  - reference: PMID:33522091
    reference_title: Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Metopic ridge, brachycephaly, mild micrognathia, synophrys, apparently long tongue, cutis marmorata;
      square finger tips, moderate soft tissue syndactyly of toes 2 and 3, broad great toes and thumbs,
      wide sandal gap deformities
    explanation: >-
      Patient 7 has broad great toes, also described in several other Table 2 cases.
- name: Micrognathia
  category: Craniofacial
  phenotype_term:
    preferred_term: Micrognathia
    term:
      id: HP:0000347
      label: Micrognathia
  description: >-
    A small mandible is documented in multiple individuals; retrognathia is separately reported and is
    not automatically treated as mandibular hypoplasia.
  evidence:
  - reference: PMID:33522091
    reference_title: Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Metopic ridge, brachycephaly, mild micrognathia, synophrys, apparently long tongue, cutis marmorata;
      square finger tips, moderate soft tissue syndactyly of toes 2 and 3, broad great toes and thumbs,
      wide sandal gap deformities
    explanation: >-
      Table 2 explicitly identifies mild micrognathia in patient 7.
- name: High Palate
  category: Craniofacial
  phenotype_term:
    preferred_term: High palate
    term:
      id: HP:0000218
      label: High palate
  description: >-
    A high or high-arched palate is reported in several individuals.
  evidence:
  - reference: PMID:33522091
    reference_title: Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Right microtia with over‐folded helix, epicanthal folds, upslanting palpebral fissures, high palate,
      micrognathia, bulbous nasal tip; small body habitus (including hands and feet), fine hair on the
      back, one hyperpigmented and one hypopigmented macule
    explanation: >-
      Table 2 records a high palate in patient 12; it is also reported in patients 6, 11 and 22.
- name: Thin Upper Lip Vermilion
  category: Craniofacial
  phenotype_term:
    preferred_term: Thin upper lip vermilion
    term:
      id: HP:0000219
      label: Thin upper lip vermilion
  description: >-
    Thin upper-lip vermilion is part of the variable facial phenotype.
  evidence:
  - reference: PMID:33522091
    reference_title: Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Mild facial dysmorphism—short palpebral fissures, thin upper lip lateral flaring of eyebrows | No
      | None | Normal brain MRI | EEG abnormalities, focal temporoparietal left, but no clinical seizures
    explanation: >-
      Table 2 records a thin upper lip in patient 24, with similar findings in other individuals.
- name: Epicanthus
  category: Craniofacial
  phenotype_term:
    preferred_term: Epicanthus
    term:
      id: HP:0000286
      label: Epicanthus
  description: >-
    Epicanthal folds recur among the reported facial findings.
  evidence:
  - reference: PMID:33522091
    reference_title: Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Bilateral epicanthal folds, slightly short palpebral fissures, tubular nose, flat cheekbones, fetal
      fingertip pads, mild 2–3 syndactyly of the feet, borderline low tone
    explanation: >-
      Table 2 explicitly documents bilateral epicanthal folds in patient 1.
- name: Upslanted Palpebral Fissures
  category: Craniofacial
  phenotype_term:
    preferred_term: Upslanted palpebral fissure
    term:
      id: HP:0000582
      label: Upslanted palpebral fissure
  description: >-
    Upslanting palpebral fissures occur in some affected individuals.
  evidence:
  - reference: PMID:33522091
    reference_title: Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Right microtia with over‐folded helix, epicanthal folds, upslanting palpebral fissures, high palate,
      micrognathia, bulbous nasal tip; small body habitus (including hands and feet), fine hair on the
      back, one hyperpigmented and one hypopigmented macule
    explanation: >-
      Table 2 records upslanting palpebral fissures in patient 12; similar observations occur in patients
      19, 21 and 25.
- name: Short Palpebral Fissures
  category: Craniofacial
  phenotype_term:
    preferred_term: Short palpebral fissure
    term:
      id: HP:0012745
      label: Short palpebral fissure
  description: >-
    Short palpebral fissures are reported; a description of narrow fissures alone is not sufficient to
    infer reduced horizontal length.
  evidence:
  - reference: PMID:33522091
    reference_title: Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Bilateral epicanthal folds, slightly short palpebral fissures, tubular nose, flat cheekbones, fetal
      fingertip pads, mild 2–3 syndactyly of the feet, borderline low tone
    explanation: >-
      Patient 1 explicitly has slightly short palpebral fissures.
- name: Broad Lateral Eyebrows
  category: Craniofacial
  phenotype_term:
    preferred_term: Broad lateral eyebrow
    term:
      id: HP:0007933
      label: Broad lateral eyebrow
  description: >-
    Lateral flaring of the eyebrows occurs in the variable facial phenotype.
  evidence:
  - reference: PMID:33522091
    reference_title: Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Mild facial dysmorphism—short palpebral fissures, thin upper lip lateral flaring of eyebrows | No
      | None | Normal brain MRI | EEG abnormalities, focal temporoparietal left, but no clinical seizures
    explanation: >-
      The lateral eyebrow flaring in patient 24 maps to broad lateral eyebrow.
- name: Constipation
  category: Gastrointestinal
  phenotype_term:
    preferred_term: Constipation
    term:
      id: HP:0002019
      label: Constipation
  description: >-
    Constipation has been reported alongside feeding and growth difficulties; no syndrome-wide prevalence
    estimate is established.
  evidence:
  - reference: PMID:33522091
    reference_title: Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      History of feeding difficulties with oral aversion, GERD, poor weight gain and constipation. Diagnosed
      with global developmental delay
    explanation: >-
      Patient 1 has constipation; Table 2 also documents it in patients 7 and 19.
- name: Cafe-au-Lait Macules
  category: Dermatologic
  phenotype_term:
    preferred_term: Cafe-au-lait spot
    term:
      id: HP:0000957
      label: Cafe-au-lait spot
  description: >-
    Cafe-au-lait macules have been described in several individuals. Their presence is not specific for
    BPTF-related disease.
  evidence:
  - reference: PMID:33522091
    reference_title: Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Low set ears, slightly upslanting palpebral fissures, epicanthal folds, 3 small irregular café au
      lait macules, unilateral single palmar crease
    explanation: >-
      Table 2 records cafe-au-lait macules in patient 25; similar observations occur in patients 5 and
      26.
- name: Kyphosis
  category: Musculoskeletal
  phenotype_term:
    preferred_term: Kyphosis
    term:
      id: HP:0002808
      label: Kyphosis
  description: >-
    Thoracic kyphosis is reported in addition to scoliosis.
  evidence:
  - reference: PMID:33522091
    reference_title: Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Thoracic kyphosis, sandal gap both feet, 2–3 syndactyly of both feet, broad great toes, long slender
      fingers
    explanation: >-
      Table 2 records thoracic kyphosis in patient 20; patient 5 also has a mild thoracic kyphotic deformity.
- name: Hypermetropia
  category: Ophthalmologic
  phenotype_term:
    preferred_term: Hypermetropia
    term:
      id: HP:0000540
      label: Hypermetropia
  description: >-
    Hyperopia is reported, sometimes with exotropia and use of corrective glasses.
  evidence:
  - reference: PMID:33522091
    reference_title: Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      First toe bilaterally is slightly laterally deviated and a little bit broad | Stable hyperopia and
      alternating exotropia, wears glasses
    explanation: >-
      The eye-anomaly cell for patient 21 documents hyperopia and glasses; hypermetropia is also listed
      for patient 26.
- name: Astigmatism
  category: Ophthalmologic
  phenotype_term:
    preferred_term: Astigmatism
    term:
      id: HP:0000483
      label: Astigmatism
  description: >-
    Astigmatism is reported with myopia in some individuals.
  evidence:
  - reference: PMID:33522091
    reference_title: Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Epicanthal folds, prominent pointed helices with prominent antihelices; prominent nasal root, mild
      bulbous nasal tip | Astigmatism, myopia, right eye exotropia
    explanation: >-
      Patient 8 has astigmatism and myopia; patient 1 also has this combination.
- name: Strabismus
  category: Ophthalmologic
  phenotype_term:
    preferred_term: Strabismus
    term:
      id: HP:0000486
      label: Strabismus
  description: >-
    Ocular misalignment includes exotropia, a resolved convergent squint, and transient strabismus when
    tired.
  evidence:
  - reference: PMID:33522091
    reference_title: Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Lateral flaring of eyebrows, narrow palpebral fissures, prominent ears and cheekbones, small mouth,
      micrognathia | Transient strabismus when tired
    explanation: >-
      Patient 17 illustrates strabismus beyond the separately recorded exotropia phenotype.
- name: Decreased Body Weight
  category: Growth
  phenotype_term:
    preferred_term: Decreased body weight
    term:
      id: HP:0004325
      label: Decreased body weight
  description: >-
    Weight below the third percentile was present in 10 of 19 individuals with measurements at the most
    recent assessment in the 2021 cohort. This cross-sectional finding does not by itself establish failure
    to thrive.
  evidence:
  - reference: PMID:33522091
    reference_title: Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      At the time of their most recent clinical assessment, 5/20 (25%) individuals exhibited short stature
      for age and 10/19 (53%) individuals had decreased weight for age (based on measurements less than
      the third percentiles for height and weight respectively).
    explanation: >-
      Provides the measured low-weight fraction independently of diagnoses of poor weight gain or malnutrition.
- name: Growth Hormone Deficiency on Stimulation Testing
  category: Endocrine
  phenotype_term:
    preferred_term: Decreased response to growth hormone stimulation test
    term:
      id: HP:0000824
      label: Decreased response to growth hormone stimulation test
  description: >-
    Reduced stimulated GH peaks were documented in two boys in the 2023 report: 4.39 and 6.36 ng/ml. This
    finding does not establish growth hormone deficiency as the cause of short stature in all individuals.
  evidence:
  - reference: PMID:36153657
    reference_title: "The effect of growth hormone treatment in children with novel BPTF gene variants: A report of two cases and literature review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      He was diagnosed with growth hormone deficiency (GHD), with a growth hormone (GH) peak of 4.39 ng/ml
      in both arginine and levodopa stimulation tests.
    explanation: >-
      Directly supports decreased response to growth hormone stimulation testing in patient 1.
  - reference: PMID:36153657
    reference_title: "The effect of growth hormone treatment in children with novel BPTF gene variants: A report of two cases and literature review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      He was also diagnosed with GHD, with a GH peak of 6.36 ng/ml in both arginine and levodopa stimulation
      tests.
    explanation: >-
      Directly supports reduced stimulated GH in patient 2.
- name: Autism
  category: Neurobehavioral
  phenotype_term:
    preferred_term: Autism
    term:
      id: HP:0000717
      label: Autism
  description: >-
    Autism was recorded in three individuals in the 2021 cohort. Assessment was not uniform across the
    cohort, and this count is not used as a population frequency.
  evidence:
  - reference: PMID:33522091
    reference_title: Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      ID | Variant | Sex | Age | DD/ID | Speech delay | Motor delay | Hypotonia | Autism | ADHD | Dysmorphic
      features ... Patient 3 | c.255delC (p.Ser86Alafs*151) | F | 22 years | + | + | + | + | + | + | Prominent
      nasal ridge, thin upper lip
    explanation: >-
      Table 2 marks autism present in patient 3; patients 14 and 17 are also marked positive. The heading
      is retained to identify the table columns.
- name: Attention Deficit Hyperactivity Disorder
  category: Neurobehavioral
  phenotype_term:
    preferred_term: Attention deficit hyperactivity disorder
    term:
      id: HP:0007018
      label: Attention deficit hyperactivity disorder
  description: >-
    ADHD was recorded in three individuals in the 2021 cohort. Missing assessments prevent a reliable
    syndrome-wide prevalence estimate.
  evidence:
  - reference: PMID:33522091
    reference_title: Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      ID | Variant | Sex | Age | DD/ID | Speech delay | Motor delay | Hypotonia | Autism | ADHD | Dysmorphic
      features ... Patient 3 | c.255delC (p.Ser86Alafs*151) | F | 22 years | + | + | + | + | + | + | Prominent
      nasal ridge, thin upper lip
    explanation: >-
      Table 2 marks ADHD present in patient 3; patients 7 and 17 are also marked positive. The heading
      identifies the otherwise ambiguous plus signs.
- name: Microcephaly
  category: Growth
  phenotype_term:
    preferred_term: Microcephaly
    term:
      id: HP:0000252
      label: Microcephaly
  description: >-
    This general phenotype includes congenital and postnatal small head circumference. The separate
    Postnatal Microcephaly record captures the timing-specific subset. The 2021 narrative reported
    4/10 below the third percentile at birth and 12/20 at the latest assessment; these are different subsets,
    not a paired longitudinal estimate.
  evidence:
  - reference: PMID:33522091
    reference_title: Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Though head circumferences were not provided for every individual, consistent with previous observations
      (Stankiewicz et al., 2017), 12/20 (60%) individuals demonstrated a head circumference less than
      the third percentile for age.
    explanation: >-
      Supports microcephaly without assuming postnatal onset for every individual.
treatments:
- name: Supportive and Developmental Therapy
  description: >-
    There is no disease-modifying therapy for NEDDFL. Management is supportive
    and centres on early intervention: speech and language therapy (given the
    disproportionate speech delay), physical and occupational therapy for motor
    delay and hypotonia, educational support, nutritional support for poor
    weight gain and feeding difficulty, and periodic monitoring for scoliosis
    and ophthalmologic problems.
  action_category: THERAPEUTIC
  therapeutic_modality: BEHAVIORAL
  treatment_term:
    preferred_term: supportive care
    term:
      id: NCIT:C15747
      label: Supportive Care
  target_phenotypes:
  - preferred_term: Delayed speech and language development
    term:
      id: HP:0000750
      label: Delayed speech and language development
  - preferred_term: Motor delay
    term:
      id: HP:0001270
      label: Motor delay
  evidence:
  - reference: PMID:33522091
    reference_title: "Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      While it is unclear how significant the degree of scoliosis was within
      individuals, careful examination and monitoring for this clinical finding
      are also recommended.
    explanation: >-
      Supports scoliosis surveillance. The quoted recommendation does not evaluate developmental
      therapies or establish their syndrome-specific efficacy.

- name: Recombinant Human Growth Hormone
  description: >-
    Two boys with short stature and growth hormone deficiency on stimulation testing received rhGH in
    the 2023 report. One gained 25.6 cm (+1.63 SD) over 3.5 years; the other gained 2.9 cm (+0.18 SD)
    over four months before treatment stopped for financial reasons. These uncontrolled observations do
    not establish long-term efficacy, safety or benefit in individuals without growth hormone deficiency.
  action_category: THERAPEUTIC
  therapeutic_modality: PROTEIN_REPLACEMENT
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: recombinant human growth hormone (somatropin)
      term:
        id: NCIT:C837
        label: Somatropin
  target_phenotypes:
  - preferred_term: Short stature
    term:
      id: HP:0004322
      label: Short stature
  evidence:
  - reference: PMID:36153657
    reference_title: "The effect of growth hormone treatment in children with novel BPTF gene variants: A report of two cases and literature review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Both children had short stature and responded to recombinant human growth
      hormone (rhGH) treatment - the first report of this therapy in NEDDFL
      patients.
    explanation: >-
      First and, to date, principal report of growth hormone therapy in NEDDFL.
  - reference: PMID:36153657
    reference_title: "The effect of growth hormone treatment in children with novel BPTF gene variants: A report of two cases and literature review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The salutary effect of rhGH in the NEDDFL is documented.
    explanation: >-
      Authors' summary conclusion from two uncontrolled cases with no comparator; this does not
      establish a general treatment effect or long-term safety.

- name: Antiseizure Medication
  description: >-
    Levetiracetam was commonly used in the selected BPTF electroclinical series and was associated with
    reduced seizure frequency in 67% of treated cases as reported by the authors. This observational result
    is not a comparative efficacy estimate. Valproate and vagus nerve stimulation were also reported in
    the 2021 cohort. The 27% drug-resistance figure describes the selected electroclinical series and
    should not be read as a rate among all individuals with NEDDFL.
  action_category: THERAPEUTIC
  therapeutic_modality: SMALL_MOLECULE
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: levetiracetam
      term:
        id: CHEBI:6437
        label: levetiracetam
  target_phenotypes:
  - preferred_term: Seizure
    term:
      id: HP:0001250
      label: Seizure
  evidence:
  - reference: PMID:38936258
    reference_title: "Epilepsy as a Novel Phenotype of BPTF-Related Disorders."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Levetiracetam was widely used and reduced seizure frequency in 67% of the
      cases.
    explanation: >-
      Reports an observational treatment response in selected patients, without a randomized comparison.

- name: Cyclical Vomiting Syndrome Therapy
  description: >-
    Acute treatment of cyclical vomiting episodes with ondansetron or
    domperidone, and prophylaxis with cyproheptadine, domperidone, or
    levetiracetam combined with lamotrigine, were all associated with clinical
    benefit in the reported BPTF series. Evidence is observational and from a
    single 15-individual questionnaire study.
  action_category: THERAPEUTIC
  therapeutic_modality: SMALL_MOLECULE
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: ondansetron
      term:
        id: CHEBI:7773
        label: Ondansetron
    - preferred_term: cyproheptadine
      term:
        id: CHEBI:4046
        label: cyproheptadine
  target_phenotypes:
  - preferred_term: Episodic vomiting
    term:
      id: HP:0002572
      label: Episodic vomiting
  evidence:
  - reference: PMID:40614698
    reference_title: "Cyclical Vomiting Syndrome in Individuals With BPTF Haploinsufficiency."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Acute therapy (ondansetron or domperidone) was administered in 42.8% of
      cases, and prophylactic therapy was provided in 57.1% of cases with
      cyproheptadine, levetiracetam combined with lamotrigine, and domperidone;
      all therapies were associated with clinical benefit.
    explanation: >-
      Observational report of benefit from acute and prophylactic CVS therapy;
      the uncontrolled series does not separate treatment effects from other influences on symptoms.

- name: Genetic Counseling
  description: >-
    Counseling addresses autosomal dominant inheritance and variable expressivity. A heterozygous parent
    has a 50% probability of transmitting the variant in each pregnancy; this is not a quantified probability
    of a particular clinical severity. Parental testing can identify inherited variants in mildly affected
    relatives. An apparently de novo result leaves a residual recurrence risk from possible parental germline
    mosaicism.
  action_category: COUNSELING_INFORMATIONAL
  therapeutic_modality: BEHAVIORAL
  treatment_term:
    preferred_term: genetic counseling
    term:
      id: NCIT:C15240
      label: Genetic Counseling
  evidence:
  - reference: PMID:33522091
    reference_title: "Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Our study has also uncovered four cases of inherited BPTF variants,
      providing some insight into the penetrance and expressivity of NEDDFL.
    explanation: >-
      Documented inherited variants are the basis for counseling about parental
      testing and recurrence risk.

- name: Gastrostomy Feeding
  action_category: THERAPEUTIC
  therapeutic_modality: SURGERY
  treatment_term:
    preferred_term: Gastrostomy Tube Procedure
    term:
      id: NCIT:C157864
      label: Gastrostomy Tube Procedure
  description: >-
    Gastrostomy was used for severe feeding difficulty or failure to thrive in two reported individuals.
    The clinical table documents use, without quantifying nutritional benefit or procedural outcomes.
  target_phenotypes:
  - preferred_term: Feeding difficulties
    term:
      id: HP:0011968
      label: Feeding difficulties
  evidence:
  - reference: PMID:33522091
    reference_title: Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Initial failure to thrive requiring gastrostomy; recurrent bacterial infections as a young child,
      requiring regular immunoglobulin infusions until age 4 y.
    explanation: >-
      Table 2 documents gastrostomy for patient 9; the infection history is contextual and does not establish
      a general immunodeficiency mechanism.
  - reference: PMID:33522091
    reference_title: Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Severe feeding problems requiring gastrostomy; congenitally corrected transposition of the great
      arteries. Mild to moderate intellectual disability (IQ 57).
    explanation: >-
      Patient 18 also required gastrostomy for feeding problems.
- name: Scoliosis Surveillance and Bracing
  action_category: THERAPEUTIC
  therapeutic_modality: DEVICE
  treatment_term:
    preferred_term: orthopedic bracing
  description: >-
    The 2021 cohort authors recommend monitoring for scoliosis. One individual had improved thoracolumbar
    scoliosis after previously requiring bracing; the report does not isolate the effect of bracing or
    establish a syndrome-specific treatment protocol.
  target_phenotypes:
  - preferred_term: Scoliosis
    term:
      id: HP:0002650
      label: Scoliosis
  evidence:
  - reference: PMID:33522091
    reference_title: Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Thoracolumbar scoliosis (improved ‐ previously required bracing) and leg length discrepancy; butterfly
      vertebra at T12 and questionable fusion of right posterolateral aspects of T5 and T6 vertebral bodies
    explanation: >-
      Patient 21 provides case-level evidence of brace use; improvement is not a controlled efficacy estimate.
  notes: >-
    Needs a treatment-action term for orthopedic brace use. The retrieved NCIT:C86054 Brace is a device
    term and does not satisfy the intervention binding; its presence does not justify substituting an
    unrelated procedure.
- name: Vagus Nerve Stimulation
  action_category: THERAPEUTIC
  therapeutic_modality: DEVICE
  treatment_term:
    preferred_term: implanted vagus nerve stimulation
  description: >-
    Vagal nerve stimulator placement is reported in one individual with focal epilepsy. The source describes
    medication-associated seizure control and recent stimulator placement, without an outcome attributable
    specifically to stimulation.
  target_phenotypes:
  - preferred_term: Seizure
    term:
      id: HP:0001250
      label: Seizure
    onset:
      onset_category: CHILDHOOD
  notes: >-
    Needs an exact treatment-action term. OLS searches for vagus nerve stimulation and neurostimulation
    returned a transcutaneous auricular procedure and unrelated spinal procedures. NCIT:C21025 describes
    electroanalgesia for neuropathic pain, so it is not used for this epilepsy intervention.
  evidence:
  - reference: PMID:33522091
    reference_title: Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Complex focal seizures with impaired awareness of frontal lobe origin beginning at age 7 y, controlled
      by medication with recent vagal nerve stimulator placement
    explanation: >-
      Table 2 documents stimulator placement in patient 21 without establishing its efficacy.
animal_models:
- name: Bptf forebrain-conditional knockout mouse
  species: Mus musculus
  genotype: Emx1-Cre forebrain-conditional Bptf knockout (Bptf cKO)
  category: Conditional knockout mouse model of NEDDFL
  description: >-
    Forebrain-specific Bptf knockout generated with Emx1-Cre causes severe cortical hypoplasia, increased
    death of newly postmitotic neurons and altered cortical neuronal marker distribution. A reduced 24-hour
    cell-cycle exit fraction suggests delayed differentiation or a longer cycle; cycle length was not
    directly timed. Brain weight is reduced at birth, whereas body weight diverges after birth. The mice
    survive to adulthood, with largely nonprogressive gross anatomy; normal home-cage appearance is not
    a formal behavioral or seizure assessment.
  notes: >-
    The larger-brain Smarca1 comparator in the original study is the exon-6 deletion allele producing
    internally truncated protein. Later complete-null experiments showed near-normal cortical size and
    support compensation by SMARCA5. These allele-specific effects limit use of an ATPase perturbation
    as a substitute for BPTF loss. Conditional heterozygotes also showed increased cleaved-caspase-3 staining
    at P7, so the study does not establish complete absence of heterozygous effects.
  modeled_mechanisms:
  - target: Delayed Neural Progenitor Cell-Cycle Exit
    relationship: RECAPITULATES
    fidelity: MODERATE
    description: >-
      Measures this candidate mechanism in a complete forebrain conditional knockout.
    readouts:
    - name: Fraction of labeled cells exiting the cycle over 24 hours
      target: Delayed Neural Progenitor Cell-Cycle Exit
      direction: DECREASED
      description: >-
        EdU-positive, Ki67-negative fraction after an E14.5 pulse and E15.5 harvest.
      interpretation: >-
        Reduced cycle exit supports delayed differentiation or longer cycle duration; cycle length itself
        was inferred.
    limitations: >-
      The complete tissue-specific knockout differs from human heterozygous BPTF disease. Human confirmation
      is lacking.
    evidence:
    - reference: url:https://pmc.ncbi.nlm.nih.gov/articles/PMC9558838/
      reference_title: Generation of a mouse model of the neurodevelopmental disorder with dysmorphic facies and distal limb anomalies syndrome - PMC
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: Taken together, the cortical progenitor cells of the ... cKO mice show no blocks in the cell cycle with similar cell proportions in the S- and M-phase to the control samples. However, fewer cells exited the cell cycle in a 24-h period suggesting that cell cycle length was prolonged, which could account for the slight reduction in IPC number.
      explanation: >-
        Separates the measured cell-cycle exit fraction from the inferred cycle length and preserves negative
        proliferation findings.
  - target: Increased Neuronal Apoptosis
    relationship: RECAPITULATES
    fidelity: MODERATE
    description: >-
      Measures this candidate mechanism in a complete forebrain conditional knockout.
    readouts:
    - name: Cell death in intermediate zone and cortical plate
      target: Increased Neuronal Apoptosis
      direction: INCREASED
      biological_processes:
      - preferred_term: apoptotic process
        term:
          id: GO:0006915
          label: apoptotic process
      description: >-
        Cleaved-caspase-3 staining in differentiating neuronal regions; ventricular-zone levels were largely
        unchanged at E15.5.
      interpretation: >-
        The spatial distribution implicates newly postmitotic neurons rather than proving generalized
        progenitor death.
    limitations: >-
      The complete tissue-specific knockout differs from human heterozygous BPTF disease. Human confirmation
      is lacking.
    evidence:
    - reference: url:https://pmc.ncbi.nlm.nih.gov/articles/PMC9558838/
      reference_title: Generation of a mouse model of the neurodevelopmental disorder with dysmorphic facies and distal limb anomalies syndrome - PMC
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: We conclude from this data that a high incidence of cell death is a major contributor to the reduction in cortical size and that this occurs as the neurons become postmitotic, initiate their terminal differentiation program, and migrate toward their final laminar position.
      explanation: >-
        Localizes the major cell-death contribution to differentiating neurons in the conditional-null
        model.
  - target: Impaired Cortical Neuron Fate Specification
    relationship: RECAPITULATES
    fidelity: MODERATE
    description: >-
      Measures this candidate mechanism in a complete forebrain conditional knockout.
    readouts:
    - name: Ctip2-high layer V neuron proportion
      target: Impaired Cortical Neuron Fate Specification
      direction: DECREASED
      description: >-
        Ctip2-high layer V cell counts are markedly reduced, with changes in Ctip2-low cell distribution
        across layers.
      interpretation: >-
        Layer-specific marker counts reflect altered identity or maturation as well as possible changes
        in cell number; they are not a direct birth-rate measurement.
    - name: Layer-specific Ctip2 regulation
      target: Impaired Cortical Neuron Fate Specification
      direction: ALTERED
      biological_processes:
      - preferred_term: cerebral cortex neuron differentiation
        term:
          id: GO:0021895
          label: cerebral cortex neuron differentiation
      description: >-
        Ctip2 expression and layer distribution change despite preserved bulk Ctip2 protein and transcript
        levels and no reduction in birth-dated EdU/Ctip2-colabeled cells.
      interpretation: >-
        The combination supports abnormal terminal differentiation and marker regulation rather than absence
        of this neuronal class.
    limitations: >-
      The complete tissue-specific knockout differs from human heterozygous BPTF disease. Human confirmation
      is lacking.
    evidence:
    - reference: url:https://pmc.ncbi.nlm.nih.gov/articles/PMC9558838/
      reference_title: Generation of a mouse model of the neurodevelopmental disorder with dysmorphic facies and distal limb anomalies syndrome - PMC
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: Immunoblots suggested the overall levels of Ctip2 were not markedly different than in the control extracts
      explanation: >-
        Preserves the negative bulk-protein result despite altered layer-specific Ctip2 staining.
    - reference: url:https://pmc.ncbi.nlm.nih.gov/articles/PMC9558838/
      reference_title: Generation of a mouse model of the neurodevelopmental disorder with dysmorphic facies and distal limb anomalies syndrome - PMC
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: suggesting that these cells are specified but have impaired Ctip2 regulation that alters lamination and terminal expression levels.
      explanation: >-
        Interpretation of the birth-dating experiment; the neuron class is not simply absent at birth.
  - target: Cortical Hypoplasia
    relationship: RECAPITULATES
    fidelity: MODERATE
    description: >-
      Reduced cortical size is directly observed in the conditional-null model.
    readouts:
    - name: Cortical size
      target: Cortical Hypoplasia
      direction: DECREASED
      description: >-
        Histological cortical size and forebrain weight are reduced relative to controls.
      interpretation: >-
        Direct model evidence for tissue hypoplasia, without establishing the same anatomical lesion in
        every human case.
    limitations: >-
      Complete forebrain loss differs from human heterozygous BPTF variants. Human MRI abnormalities are
      heterogeneous.
    evidence:
    - reference: PMID:35604347
      reference_title: "Generation of a mouse model of the neurodevelopmental disorder with dysmorphic facies and distal limb anomalies syndrome."
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: >-
        The Bptf cKO mice were born in normal Mendelian ratios, survived to
        adulthood but were smaller in size with severe cortical hypoplasia.
      explanation: >-
        Establishes cortical hypoplasia with reduced body size as the tissue-level
        phenotype of forebrain Bptf loss.
    - reference: url:https://pmc.ncbi.nlm.nih.gov/articles/PMC9558838/
      reference_title: Generation of a mouse model of the neurodevelopmental disorder with dysmorphic facies and distal limb anomalies syndrome - PMC
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: The gross morphology of the hypoplastic forebrain remained identical to the P12 mice as the mice aged
      explanation: >-
        Supports a developmental, grossly nonprogressive anatomical phenotype in the model.
  evidence:
  - reference: PMID:35604347
    reference_title: "Generation of a mouse model of the neurodevelopmental disorder with dysmorphic facies and distal limb anomalies syndrome."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      To model the NEDDFL syndrome, we generated forebrain-specific Bptf
      knockout (Bptf conditional Knockout (cKO)) mice.
    explanation: >-
      Establishes the model's purpose and construction.
  - reference: PMID:35604347
    reference_title: "Generation of a mouse model of the neurodevelopmental disorder with dysmorphic facies and distal limb anomalies syndrome."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      Surprisingly, ablation of Smarca1 resulted in mice with enlarged brains, a
      direct contrast to the phenotype of NEDDFL patients.
    explanation: >-
      The original paper summarizes the enlarged-brain comparator; the subsequent study distinguishes
      the exon-6 deletion allele from a complete Smarca1 null.

- name: bptf CRISPR F0 crispant zebrafish
  species: Danio rerio
  genotype: CRISPR-Cas9 bptf F0 crispant
  category: CRISPR F0 knockout zebrafish model
  description: >-
    CRISPR-Cas9 knockout of zebrafish bptf produces F0 mutant larvae with
    significantly reduced head size, increased apoptosis by TUNEL staining, and
    a substantially increased ceratohyal angle indicating abnormal craniofacial
    patterning (PMID:28942966). This model recapitulates both the microcephaly
    and the craniofacial dimensions of NEDDFL.
  modeled_mechanisms:
  - target: Reduced Brain Growth
    relationship: PARTIALLY_RECAPITULATES
    fidelity: MODERATE
    description: >-
      Reduced head size in bptf F0 larvae is the cross-species correlate of the
      human microcephaly.
    readouts:
    - name: Larval head size
      target: Reduced Brain Growth
      direction: DECREASED
      description: >-
        Head size of bptf F0 crispant larvae versus control larvae.
      interpretation: >-
        Significantly reduced head size is the model's microcephaly readout; it
        indexes reduced brain growth but not the postnatal timing of the human
        phenotype.
    limitations: >-
      F0 crispants are mosaic genome-edited larvae. Reduced head size does not establish human postnatal
      timing or a defined heterozygous dosage response.
    evidence:
    - reference: PMID:28942966
      reference_title: "Haploinsufficiency of the Chromatin Remodeler BPTF Causes Syndromic Developmental and Speech Delay, Postnatal Microcephaly, and Dysmorphic Features."
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: >-
        Using CRISPR-Cas9 genome editing of bptf in zebrafish to induce a loss of
        gene function, we observed a significant reduction in head size of F0
        mutants compared to control larvae.
      explanation: >-
        Reduced larval head size supports a developmental role for bptf but does not capture the
        postnatal timing of some human microcephaly presentations or quantify human heterozygous effects.
  - target: Disrupted Craniofacial and Limb Patterning
    relationship: PARTIALLY_RECAPITULATES
    description: >-
      Increased ceratohyal angle is an established quantitative readout of
      disrupted craniofacial patterning, and is the direct experimental support
      for the craniofacial arm of this node.
    readouts:
    - name: Ceratohyal angle
      target: Disrupted Craniofacial and Limb Patterning
      direction: INCREASED
      description: >-
        Angle of the ceratohyal cartilage of the craniofacial skeleton in bptf
        F0 crispants versus controls.
      interpretation: >-
        A substantially widened ceratohyal angle is the established quantitative
        index of abnormal craniofacial patterning in zebrafish.
    limitations: >-
      Supports the craniofacial arm only. No model has yet demonstrated the
      distal limb arm of this node, which is why the node is marked PROVISIONAL.
    evidence:
    - reference: PMID:28942966
      reference_title: "Haploinsufficiency of the Chromatin Remodeler BPTF Causes Syndromic Developmental and Speech Delay, Postnatal Microcephaly, and Dysmorphic Features."
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: >-
        we observed a substantial increase of the ceratohyal angle of the
        craniofacial skeleton in bptf F0 mutants, indicating abnormal craniofacial
        patterning
      explanation: >-
        Direct experimental demonstration of disrupted craniofacial patterning on
        bptf loss.
  evidence:
  - reference: PMID:28942966
    reference_title: "Haploinsufficiency of the Chromatin Remodeler BPTF Causes Syndromic Developmental and Speech Delay, Postnatal Microcephaly, and Dysmorphic Features."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      Using CRISPR-Cas9 genome editing of bptf in zebrafish to induce a loss of
      gene function, we observed a significant reduction in head size of F0
      mutants compared to control larvae.
    explanation: >-
      Establishes the zebrafish model and its microcephaly readout.

- name: Constitutive Bptf-null mouse embryo
  species: Mus musculus
  genotype: Homozygous Bptf gene-trap or exon-2 deletion; equivalent early embryonic phenotypes
  category: Constitutive null mouse embryo
  description: >-
    Gene-trap and exon-2-deletion homozygotes develop postimplantation growth defects, fail to establish
    a functional distal/anterior visceral endoderm and primitive streak, and are resorbed by E8.5. Mitotic-marker
    staining is reduced without a generalized increase in TUNEL staining. These findings establish early
    embryonic gene essentiality, not the phenotype of human heterozygous disease.
  modeled_mechanisms:
  - target: BPTF Haploinsufficiency
    relationship: PERTURBS
    fidelity: LOW
    description: >-
      Perturbs Bptf through complete loss, providing an essentiality comparison for the human heterozygous
      disorder. It does not quantify a heterozygous dose-response relationship.
    readouts:
    - name: Post-implantation embryonic survival
      target: BPTF Haploinsufficiency
      direction: DECREASED
      description: >-
        Survival of constitutive Bptf-null embryos, which show post-implantation
        growth defects and are resorbed by E8.5.
      interpretation: >-
        Complete-loss embryonic lethality demonstrates essentiality and cannot establish the consequences
        of a heterozygous variant.
    limitations: >-
      Both alleles are disrupted, whereas affected humans typically carry one pathogenic allele. The study
      also reports a maternal effect on embryo survival in gene-trap heterozygous females, without preferential
      loss of heterozygous offspring; this is distinct from a demonstrated heterozygous neurodevelopmental
      phenotype.
    evidence:
    - reference: PMID:18974875
      reference_title: "Essential role of chromatin remodeling protein Bptf in early mouse embryos and embryonic stem cells."
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: >-
        Bptf mutants manifest growth defects at the post-implantation stage and
        are reabsorbed by E8.5.
      explanation: >-
        Demonstrates embryonic essentiality after complete Bptf loss, without measuring human haploinsufficiency.
  evidence:
  - reference: PMID:18974875
    reference_title: "Essential role of chromatin remodeling protein Bptf in early mouse embryos and embryonic stem cells."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      Bptf mutants manifest growth defects at the post-implantation stage and
      are reabsorbed by E8.5.
    explanation: >-
      Demonstrates embryonic essentiality after complete Bptf loss, without measuring human haploinsufficiency.
diagnosis:
- name: Trio Exome or Genome Sequencing
  description: >-
    Exome sequencing, neurodevelopmental gene panels and copy-number testing have identified affected
    individuals. Parental testing distinguishes de novo from inherited variants and informs interpretation.
    The cited case series document ascertainment methods rather than establishing a syndrome-specific
    diagnostic yield comparison or first-line guideline.
  diagnosis_term:
    preferred_term: whole exome sequencing
    term:
      id: NCIT:C101295
      label: Whole Exome Sequencing
  evidence:
  - reference: PMID:33522091
    reference_title: "Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Molecular testing results from exome sequencing, chromosomal microarray,
      or next‐generation sequencing panel were submitted by patients'
      healthcare providers
    explanation: >-
      Documents the diagnostic modalities through which the 26-individual
      expansion cohort was actually ascertained.
  - reference: PMID:40415676
    reference_title: "Effects of the Missense Variants on Complete Phenotype and Splicing Variant on Severe Growth Retardation in the BPTF Gene."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      BPTF gene variants were detected using whole-exome sequencing. Family
      segregation analysis was performed using sanger sequencing.
    explanation: >-
      Independent series confirming exome sequencing as the detection method,
      with Sanger segregation analysis in the family.
  - reference: PMID:36153657
    reference_title: "The effect of growth hormone treatment in children with novel BPTF gene variants: A report of two cases and literature review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The exome sequencing was performed in two probands. Sanger sequencing was
      used to confirm the identified variants both in probands and their parents.
    explanation: >-
      Shows the standard workflow of exome discovery plus Sanger confirmation in
      proband and parents.

- name: Chromosomal Microarray for 17q24.2 Copy-Number Variants
  description: >-
    Chromosomal microarray can detect BPTF-containing deletions, subject to assay resolution. Larger 17q24.2
    deletions require assessment of other affected genes. Balanced gene-disrupting rearrangements require
    appropriate structural-variant testing and cannot be excluded by a normal microarray.
  diagnosis_term:
    preferred_term: chromosomal microarray (array comparative genomic hybridization)
    term:
      id: NCIT:C18084
      label: Comparative Genomic Hybridization
  evidence:
  - reference: PMID:28942966
    reference_title: "Haploinsufficiency of the Chromatin Remodeler BPTF Causes Syndromic Developmental and Speech Delay, Postnatal Microcephaly, and Dysmorphic Features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      we report eight loss-of-function and two missense variants (eight de novo
      and two of unknown origin) in BPTF on 17q24.2
    explanation: >-
      Establishes the 17q24.2 locus that copy-number testing must cover.
  - reference: PMID:33522091
    reference_title: "Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Molecular testing results from exome sequencing, chromosomal microarray,
      or next‐generation sequencing panel were submitted by patients'
      healthcare providers
    explanation: >-
      Confirms chromosomal microarray as one of the modalities that identified
      individuals in the expansion cohort.

- name: ACMG/AMP Variant Interpretation with Parental Testing
  description: >-
    A molecular diagnosis requires a pathogenic or likely pathogenic BPTF variant interpreted with phenotype,
    inheritance, population frequency, transcript context and the expected effect of the allele. The 2021
    cohort reported 11 pathogenic, seven likely pathogenic and two uncertain variants. A VUS alone does
    not establish the diagnosis. The two missense variants in the 2025 report were also VUS, despite severe
    findings in carriers, illustrating why phenotype severity alone cannot establish pathogenicity. Truncating
    and copy-number alleles likewise require appropriate interpretation.
  diagnosis_term:
    preferred_term: genetic testing
    term:
      id: NCIT:C15709
      label: Genetic Testing
  evidence:
  - reference: PMID:33522091
    reference_title: "Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Variants were interpreted as pathogenic (11), likely pathogenic (7), or VUS
      (2) based on the current ACMG criteria.
    explanation: >-
      Documents ACMG/AMP classification as the interpretation framework and the
      residual VUS rate.
  - reference: PMID:33522091
    reference_title: "Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      it is anticipated that the finding of missense variants in BPTF may present
      a diagnostic challenge for practitioners, particularly in individuals with
      mild phenotypes
    explanation: >-
      The authors flag missense variants as the principal interpretation
      difficulty, supporting the caution that a missense VUS alone is not
      diagnostic.
  notes: >-
    Explicit negatives, recorded so their absence is not mistaken for a curation
    gap. (1) There are no formal consensus diagnostic criteria for NEDDFL;
    diagnosis is a compatible phenotype plus molecular confirmation. (2) There is
    no diagnostic biochemical, enzymatic, imaging, or circulating biomarker - a
    normal brain MRI in particular does not exclude the diagnosis, since most
    imaged individuals in the expansion cohort had normal studies. (3) No
    validated functional assay and no DNA-methylation episignature has been
    established for BPTF, despite NEDDFL being a chromatinopathy where an
    episignature might be expected; RNA sequencing and proteomics for resolving
    difficult variants remain investigational. (4) No newborn or general
    population screening exists; cascade testing is appropriate once a familial
    pathogenic variant is known.

differential_diagnoses:
- name: Neurodevelopmental disorder with dysmorphic facies and distal skeletal anomalies (ZMIZ1)
  disease_term:
    preferred_term: NEDDFSA
    term:
      id: MONDO:0032855
      label: neurodevelopmental disorder with dysmorphic facies and distal skeletal anomalies
  description: >-
    A separate autosomal dominant neurodevelopmental entity caused by
    heterozygous ZMIZ1 variants. Its MONDO label differs from this disorder's by
    a single word ("skeletal" versus "limb"), which makes it the single highest
    named-entity-confusion risk for NEDDFL in any label- or text-based search.
  distinguishing_features:
  - >-
    Molecular: ZMIZ1 versus BPTF (hgnc:3581). The gene is the only reliable
    discriminator; confirm the causative gene before importing any cohort data
    published under either "dysmorphic facies and distal ... anomalies" phrasing.
  - >-
    Nomenclature: the near-identical labels are the hazard, not the phenotypes.
    Both are dominant neurodevelopmental syndromes with dysmorphism and distal
    appendicular findings.
  notes: >-
    No literature evidence item is attached here deliberately: the point of this
    record is the identity distinction, which is established by the MONDO/OMIM
    identifiers themselves rather than by a phenotype claim. Adding a ZMIZ1
    cohort citation to a BPTF entry would reintroduce exactly the confusion this
    record exists to prevent.

- name: OTUD6B-related intellectual developmental disorder with dysmorphic facies, seizures and distal limb anomalies
  disease_term:
    preferred_term: IDDFSDA
    term:
      id: MONDO:0044319
      label: intellectual developmental disorder with dysmorphic facies, seizures, and distal limb anomalies
  description: >-
    An ultra-rare autosomal recessive multisystem disorder caused by biallelic
    OTUD6B variants (OMIM:617452), a ubiquitin-proteasome-system disorder of
    development. It shares the "dysmorphic facies ... and distal limb anomalies"
    phrasing with NEDDFL and overlaps clinically (developmental delay,
    microcephaly, dysmorphism, distal limb findings), but is mechanistically and
    genetically distinct.
  distinguishing_features:
  - >-
    Inheritance: biallelic and autosomal recessive (OTUD6B) versus heterozygous
    and autosomal dominant, typically de novo (BPTF). The inheritance mode alone
    separates them in almost every family.
  - >-
    Mechanism: impaired 26S proteasome assembly and reduced chymotrypsin-like
    proteasome activity (OTUD6B) versus impaired NURF ATP-dependent chromatin
    remodeling (BPTF).
  - >-
    Seizures are a defining, near-universal feature of the OTUD6B disorder and
    are named in its label, whereas in NEDDFL epilepsy occurs in a minority
    (about 19%) and was absent from the original clinical description.
  notes: >-
    The dismech OTUD6B entry carries the reciprocal NEC guardrail and
    deliberately excludes PMID:33522091 from all of its claims because that
    paper describes NEDDFL. The exclusion is honoured in the opposite direction
    here: no OTUD6B-specific citation is used anywhere in this BPTF entry.
  evidence:
  - reference: PMID:38936258
    reference_title: "Epilepsy as a Novel Phenotype of BPTF-Related Disorders."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Epilepsy was not included in the initial descriptions of NEDDFL, but
      emerging evidence indicates that epileptic seizures occur in some affected
      individuals.
    explanation: >-
      Supports the distinguishing feature that seizures are a late-recognized,
      minority finding in NEDDFL, unlike the OTUD6B disorder in which seizures
      are part of the disease name and the defining phenotype.

- name: Silver-Russell syndrome
  description: >-
    A clinical phenocopy hazard rather than a nomenclature hazard: the
    combination of small-for-gestational-age birth, poor postnatal growth,
    a small triangular face, and feeding difficulty can prompt an initial
    diagnosis of Silver-Russell syndrome in a child later found to have BPTF
    disruption. At least one adult carried the Silver-Russell label for 35 years
    before BPTF disruption was identified.
  distinguishing_features:
  - >-
    NEDDFL has postnatal (secondary) microcephaly, whereas relative macrocephaly
    for body size is characteristic of Silver-Russell syndrome.
  - >-
    NEDDFL has prominent speech delay and intellectual disability; cognition is
    typically preserved or only mildly affected in Silver-Russell syndrome.
  - >-
    Silver-Russell syndrome is most often caused by 11p15 loss of methylation or
    maternal uniparental disomy of chromosome 7, neither of which involves BPTF.
  notes: >-
    Recorded on the basis of the published case title (PMID:30633344,
    "Neurodevelopmental disorder with dysmorphic facies and distal limb
    anomalies syndrome due to disruption of BPTF in a 35-year-old man initially
    diagnosed with Silver-Russell syndrome"). No evidence item is attached
    because no abstract text is available for that reference in the reference
    cache, and dismech policy forbids quoting text that cannot be verified
    against a cached source.

discussions:
- discussion_id: bptf_vs_smarca1_dosage_paradox
  kind: KNOWLEDGE_GAP
  status: OPEN
  prompt: >-
    How do developmental NURF subunit composition and compensation determine the consequences of heterozygous
    BPTF loss in human cortex?
  attaches_to:
  - pathophysiology#Impaired NURF Chromatin-Remodeling Activity
  rationale: >-
    The original brain-size contrast was based on Smarca1 exon-6 deletion mice that express an internally
    truncated protein, rather than a complete null. The 2025 study found near-normal cortical size after
    complete Smarca1 loss and severe hypoplasia in Bptf conditional knockouts; double mutants were no
    more severe than Bptf loss alone. These results support a model of ATPase compensation and variant-dependent
    interference. Compensation was tested biochemically in cerebellar CERF complexes because specific
    BPTF antibodies were unavailable, so NURF subunit switching in cortex remains partly inferred. Its
    quantitative relationship to human BPTF heterozygosity remains unresolved.
  proposed_experiments:
  - experiment_id: bptf_smarca1_side_by_side_cortex
    name: Side-by-side cortical comparison of Bptf and Smarca1 conditional knockouts
    description: >-
      Compare heterozygous Bptf loss with complete and internally truncated Smarca1 alleles in matched
      cortical cell systems, measuring NURF composition, target expression and neuronal differentiation.
      Existing mouse single/double-knockout comparisons provide the complete-loss baseline.
  - experiment_id: bptf_snf2l_cooccupancy_map
    name: BPTF and SNF2L chromatin co-occupancy mapping in cortical progenitors
    description: >-
      Map BPTF chromatin occupancy in cortical progenitors and ask what fraction
      of BPTF-bound sites are also SNF2L-bound, to quantify the size of the
      NURF-independent BPTF binding compartment.
  - experiment_id: bptf_myc_axis_microcephaly_test
    name: Test whether the BPTF-MYC axis accounts for the Bptf-specific microcephaly
    description: >-
      Test whether the NURF-independent BPTF interactome, including the MYC
      cofactor axis identified by RNA-seq binding-site enrichment, accounts for
      the microcephaly that Smarca1 loss fails to reproduce.
  evidence:
  - reference: PMID:41213919
    reference_title: Pathogenic variants in SMARCA1 cause an X-linked neurodevelopmental disorder modulated by NURF complex composition.
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: Taken together, these data reveal that proper cortical development requires NURF, and that Smarca5 fully compensates when Smarca1 is completely ablated (no difference in brain size in Smarca1 KO) but not when some SMARCA1 protein is produced (e.g. Smarca1ex6del mice).
    explanation: >-
      Distinguishes complete Smarca1 loss from the internally truncated allele underlying the earlier
      macrocephaly contrast.
  - reference: PMID:41213919
    reference_title: Pathogenic variants in SMARCA1 cause an X-linked neurodevelopmental disorder modulated by NURF complex composition.
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: 'The switch to the cerebellum and analysis of the CERF complex was chosen for three reasons: (1) the lack of commercially available antibodies specific to BPTF for analysis of the NURF complex; (2) the Smarca5 cKO and Smarca1ex6del mutant animals show similar differential effects on cerebellar size to those observed in the neocortex; and (3) the CERF complex is enriched in the cerebellum27,37.'
    explanation: >-
      The biochemical experiment measures CERF composition in cerebellum, so it is indirect evidence for
      cortical NURF switching.
- discussion_id: bptf_mouse_homozygous_vs_human_haploinsufficiency
  kind: HUMAN_MODEL_MISMATCH
  status: OPEN
  prompt: >-
    Which cortical consequences of complete forebrain Bptf loss also occur in heterozygous mouse or human
    neural systems?
  attaches_to:
  - pathophysiology#Cortical Hypoplasia
  rationale: >-
    Human disease usually involves heterozygous BPTF variants, whereas the major cortical model deletes
    both alleles in the Emx1 domain. Gross heterozygous effects are limited, but increased cleaved-caspase-3
    staining at P7 was reported, so absence of all heterozygous phenotypes is not established. Conditional-null
    findings include reduced cell-cycle exit, neuronal apoptosis and altered layer-specific neuronal marker
    regulation. Their magnitude and relationship to human disease remain unresolved, and actual protein
    dosage should be measured rather than assumed to fall by exactly half.
  proposed_experiments:
  - experiment_id: bptf_het_mouse_deep_phenotyping
    name: Deep cortical phenotyping of Bptf heterozygous mice
    description: >-
      Quantify cortical volume, neuronal marker distribution, apoptosis and progenitor cycle exit in heterozygous
      mice, with direct Bptf protein measurements and age-matched controls.
  - experiment_id: bptf_het_ipsc_cortical_organoid
    name: Isogenic heterozygous BPTF-null human cortical organoids
    description: >-
      Derive isogenic human iPSC lines carrying patient BPTF null alleles in the
      heterozygous state and assay cortical organoid size, progenitor cell cycle
      length, and deep-layer neuron output against isogenic controls.
  - experiment_id: bptf_dosage_response_cross_species
    name: Cross-species BPTF dosage-response comparison
    description: >-
      Compare BPTF dosage-response curves for NURF assembly and target-gene
      expression between mouse and human cortical progenitors, to test whether
      the human system is simply steeper.
  evidence:
  - reference: PMID:35604347
    reference_title: "Generation of a mouse model of the neurodevelopmental disorder with dysmorphic facies and distal limb anomalies syndrome."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      To model the NEDDFL syndrome, we generated forebrain-specific Bptf
      knockout (Bptf conditional Knockout (cKO)) mice.
    explanation: >-
      Identifies the model whose homozygous conditional-null design is the
      source of the mismatch with the human heterozygous disorder.
datasets:
- accession: geo:GSE154700
  title: BPTF is essential for murine neocortical development
  description: >-
    Bulk forebrain RNA sequencing comparing Bptf Emx1-Cre conditional knockout and control mice at E13.5
    and birth. GEO contains four control and four knockout samples at each stage, totaling 16 samples.
  organism:
    preferred_term: Mus musculus
    term:
      id: NCBITaxon:10090
      label: Mus musculus
  data_type: BULK_RNA_SEQ
  sample_count: 16
  conditions:
  - E13.5 control and Bptf forebrain conditional knockout
  - P0 control and Bptf forebrain conditional knockout
  platform: Illumina HiSeq 4000 and Illumina NovaSeq 6000
  publication: PMID:35604347
  notes: >-
    GEO GSE154700 lists 16 samples and two platforms. The overall-design field mentions P0 only, but the
    sample list also contains eight E13.5 samples. Bulk expression at birth is affected by altered neuronal
    abundance and microglial accumulation; changes are not necessarily cell-intrinsic or direct BPTF targets.
    This complete-loss mouse dataset is not a human heterozygous disease transcriptome.
experimental_models:
- name: Bptf-null mouse embryonic stem cells and rescued embryoid bodies
  experimental_model_type: OTHER
  organism:
    preferred_term: Mus musculus
    term:
      id: NCBITaxon:10090
      label: Mus musculus
  cell_source: Engineered mouse embryonic stem-cell lines derived from CJ7 cells
  cell_types:
  - preferred_term: embryonic stem cell
    term:
      id: CL:0002322
      label: embryonic stem cell
  culture_system: Embryonic stem-cell culture, LIF withdrawal or retinoic-acid differentiation, and nine-day embryoid-body differentiation
  conditions:
  - Wild type
  - Biallelic Bptf exon-2 deletion
  - Retargeted Bptf rescue allele
  publication: PMID:18974875
  description: >-
    Bptf-null embryonic stem cells remain viable but differentiate abnormally. Embryoid bodies fail to
    form a normal outer endodermal layer and show impaired lineage-marker induction, rescued by retargeting
    a functional Bptf allele. Microarray experiments under LIF maintenance, LIF withdrawal and retinoic-acid
    differentiation show context-dependent activation and repression, including derepression of Hox clusters.
    Activin experiments preserve Smad2 phosphorylation but impair selected target-gene induction and Snf2h/l
    enhancer recruitment.
  modeled_mechanisms:
  - target: Dysregulated Developmental Gene Transcription
    relationship: RECAPITULATES
    fidelity: MODERATE
    description: >-
      Directly measures Bptf-dependent transcription during differentiation and ligand stimulation.
    readouts:
    - name: Lineage-marker induction after Bptf restoration
      target: Dysregulated Developmental Gene Transcription
      direction: RESTORED
      description: >-
        Mesodermal and endodermal transcriptional responses during embryoid-body differentiation recover
        after retargeting a functional allele.
    - name: Activin-responsive target-gene induction
      target: Dysregulated Developmental Gene Transcription
      direction: DECREASED
      description: >-
        Cer1, Gsc and T induction is impaired in Bptf-null cells despite retained Smad2 phosphorylation.
    limitations: >-
      Complete-loss mouse stem cells and early embryonic differentiation are not patient-derived heterozygous
      neural models. The findings do not establish a universal increase in apoptosis after BPTF loss.
    evidence:
    - reference: PMID:18974875
      reference_title: Essential role of chromatin remodeling protein Bptf in early mouse embryos and embryonic stem cells.
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: >-
        Reintroduction of BptfFloxed-Neo rescued the induction of mesoderm and endoderm markers during
        embryoid differentiation.
      explanation: >-
        Restoring a functional Bptf allele rescued lineage-marker induction, supporting a Bptf-dependent
        differentiation defect.
    - reference: PMID:18974875
      reference_title: Essential role of chromatin remodeling protein Bptf in early mouse embryos and embryonic stem cells.
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: >-
        ES cells readily responded to activin-A as monitored by the phosphorylation of Smad2 ... Genes
        requiring Bptf for full activation include Cer1, Gsc and T
      explanation: >-
        Activin-induced Smad2 phosphorylation was preserved, while selected downstream transcriptional
        responses depended on Bptf.
    - reference: PMID:18974875
      reference_title: Essential role of chromatin remodeling protein Bptf in early mouse embryos and embryonic stem cells.
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: >-
        Chromatin immunoprecipation of Snf2h/l and histone modifications 3me-K4H3 and 3me-K27H3 at Lefty1
        show recruitment of the Snf2h/l subunit to the neural plate specific enhancer (NPE), a region
        which contains Smad binding elements, in a Bptf and an activin-A–dependent manner.
      explanation: >-
        Enhancer recruitment of Snf2h/l depends on Bptf and activin stimulation; this supports a nuclear
        regulatory defect downstream of ligand reception.
  evidence:
  - reference: PMID:18974875
    reference_title: Essential role of chromatin remodeling protein Bptf in early mouse embryos and embryonic stem cells.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      Reintroduction of BptfFloxed-Neo rescued the induction of mesoderm and endoderm markers during embryoid
      differentiation.
    explanation: >-
      Restoring a functional Bptf allele rescued lineage-marker induction, supporting a Bptf-dependent
      differentiation defect.
  - reference: PMID:18974875
    reference_title: Essential role of chromatin remodeling protein Bptf in early mouse embryos and embryonic stem cells.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      TUNEL negative Bptf mutant (−/−) and wild type (+/+) cells have similar staining for proliferation
      markers PCNA and phosphorylated histone H3.
    explanation: >-
      The embryoid-body phenotype was not accompanied by generalized increased apoptosis or reduced proliferation-marker
      staining.
  - reference: PMID:18974875
    reference_title: Essential role of chromatin remodeling protein Bptf in early mouse embryos and embryonic stem cells.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      ES cells readily responded to activin-A as monitored by the phosphorylation of Smad2 ... Genes requiring
      Bptf for full activation include Cer1, Gsc and T
    explanation: >-
      Activin-induced Smad2 phosphorylation was preserved, while selected downstream transcriptional responses
      depended on Bptf.
  - reference: PMID:18974875
    reference_title: Essential role of chromatin remodeling protein Bptf in early mouse embryos and embryonic stem cells.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      Chromatin immunoprecipation of Snf2h/l and histone modifications 3me-K4H3 and 3me-K27H3 at Lefty1
      show recruitment of the Snf2h/l subunit to the neural plate specific enhancer (NPE), a region which
      contains Smad binding elements, in a Bptf and an activin-A–dependent manner.
    explanation: >-
      Enhancer recruitment of Snf2h/l depends on Bptf and activin stimulation; this supports a nuclear
      regulatory defect downstream of ligand reception.
  notes: >-
    The 2008 paper provides microarray and analysis data in a supplementary XLS file; no GEO accession
    was identified in the cached full text. NURF can activate or repress different gene sets depending
    on differentiation conditions.
- name: P19 Bptf-knockdown Smad-response reporter model
  experimental_model_type: CELL_LINE
  organism:
    preferred_term: Mus musculus
    term:
      id: NCBITaxon:10090
      label: Mus musculus
  cell_source: Mouse P19 embryonal carcinoma cell line
  culture_system: siRNA knockdown with Smad-binding-element or activin-response-element luciferase reporters
  publication: PMID:18974875
  description: >-
    Bptf knockdown reduces TGF-beta- and activin-responsive reporter transcription in P19 cells. Reporter
    activation remains impaired when the pathway is driven with constitutively active receptor and Smad
    constructs, supporting a nuclear co-regulatory role.
  modeled_mechanisms:
  - target: Dysregulated Developmental Gene Transcription
    relationship: RECAPITULATES
    fidelity: LOW
    description: >-
      Tests a specific transcriptional consequence of Bptf depletion.
    readouts:
    - name: Smad-response reporter activity
      target: Dysregulated Developmental Gene Transcription
      direction: DECREASED
      description: >-
        Luciferase output falls after Bptf siRNA under ligand stimulation or constitutive receptor/Smad
        activation.
    limitations: >-
      Transformed mouse cells with artificial reporters do not establish this pathway as the cause of
      human neurodevelopmental or gastrointestinal features.
    evidence:
    - reference: PMID:18974875
      reference_title: Essential role of chromatin remodeling protein Bptf in early mouse embryos and embryonic stem cells.
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: >-
        Under conditions of Bptf knockdown, we observed a significant reduction in luciferase activity
        from both reporters
      explanation: >-
        Bptf knockdown reduced both minimal Smad-binding-element and activin-response-element reporter
        activity in P19 cells.
    - reference: PMID:18974875
      reference_title: Essential role of chromatin remodeling protein Bptf in early mouse embryos and embryonic stem cells.
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: >-
        Knockdown of Bptf in P19 cells renders SBE Smad responsive elements unresponsive to constitutively
        activated Smad transcription factors.
      explanation: >-
        Reporter impairment persists with constitutive receptor/Smad activation, consistent with a downstream
        transcriptional requirement.
  evidence:
  - reference: PMID:18974875
    reference_title: Essential role of chromatin remodeling protein Bptf in early mouse embryos and embryonic stem cells.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      Under conditions of Bptf knockdown, we observed a significant reduction in luciferase activity from
      both reporters
    explanation: >-
      Bptf knockdown reduced both minimal Smad-binding-element and activin-response-element reporter activity
      in P19 cells.
  - reference: PMID:18974875
    reference_title: Essential role of chromatin remodeling protein Bptf in early mouse embryos and embryonic stem cells.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      Knockdown of Bptf in P19 cells renders SBE Smad responsive elements unresponsive to constitutively
      activated Smad transcription factors.
    explanation: >-
      Reporter impairment persists with constitutive receptor/Smad activation, consistent with a downstream
      transcriptional requirement.
variants:
- name: NM_004459.6:c.1133G>A (p.Arg378Gln)
  gene:
    preferred_term: BPTF
    term:
      id: hgnc:3581
      label: BPTF
  variant_type: single nucleotide variant
  description: >-
    Reported as likely pathogenic in the 2023 growth-hormone case series. Neither parent carried the variant,
    but parentage was not confirmed. The source classification is retained; direct functional validation
    was not reported.
  evidence:
  - reference: PMID:36153657
    reference_title: "The effect of growth hormone treatment in children with novel BPTF gene variants: A report of two cases and literature review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      In patient 1, a heterozygous c.1133G>A (p.Arg378Gln) novel missense variant was detected in BPTF
      (NM_004459.6). Both parents were wild‐type for this variant
    explanation: >-
      Identifies the transcript, substitution and parental result.
  - reference: PMID:36153657
    reference_title: "The effect of growth hormone treatment in children with novel BPTF gene variants: A report of two cases and literature review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      This variant is considered to be likely pathogenic based on the ACMG/AMP standards and guidelines
      ... This genetic abnormality is assumed de novo, but without confirmation of paternity and maternity
      (PM6).
    explanation: >-
      Records the authors' classification and the limit on de novo confirmation.
  clinical_significance: LIKELY_PATHOGENIC
- name: NM_004459.6:c.5941delC (p.Pro1981LeufsTer33)
  gene:
    preferred_term: BPTF
    term:
      id: hgnc:3581
      label: BPTF
  variant_type: deletion
  description: >-
    Frameshift reported as likely pathogenic and confirmed de novo in the second child in the 2023 series.
    Loss of function was predicted; no patient RNA or protein assay demonstrated the specific consequence.
  evidence:
  - reference: PMID:36153657
    reference_title: "The effect of growth hormone treatment in children with novel BPTF gene variants: A report of two cases and literature review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      In patient 2, a heterozygous c.5941delC (p.P1981Lfs*33) novel frameshift variant was detected in
      BPTF (NM_004459.6). Both parents were wild‐type for this variant
    explanation: >-
      Identifies the frameshift and its source transcript.
  - reference: PMID:36153657
    reference_title: "The effect of growth hormone treatment in children with novel BPTF gene variants: A report of two cases and literature review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      As in case 1, this variant is considered to be likely pathogenic based on the ACMG/AMP standards
      and guidelines ... The variant is confirmed de novo in a patient with the disease and no family
      history (PS2).
    explanation: >-
      Preserves the source classification and confirmed de novo status.
  clinical_significance: LIKELY_PATHOGENIC
- name: NM_182641.4:c.2812+1G>C
  gene:
    preferred_term: BPTF
    term:
      id: hgnc:3581
      label: BPTF
  variant_type: single nucleotide variant
  description: >-
    De novo splice-donor substitution classified as pathogenic in the 2025 report. Splicing disruption
    was predicted; the paper does not demonstrate a particular abnormal transcript or protein product.
  evidence:
  - reference: PMID:40415676
    reference_title: Effects of the Missense Variants on Complete Phenotype and Splicing Variant on Severe Growth Retardation in the BPTF Gene.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      We identified a novel heterozygous non‐coding variant in the BPTF (NM_182641.4): c.2812+1G>C through
      WES. This splice‐site variant is likely to disrupt normal splicing of the BPTF gene, which could
      result in abnormal mRNA processing and produce a non‐functional or truncated protein.
    explanation: >-
      Distinguishes the physical donor-site substitution from its predicted RNA consequence.
  - reference: PMID:40415676
    reference_title: Effects of the Missense Variants on Complete Phenotype and Splicing Variant on Severe Growth Retardation in the BPTF Gene.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      c.2812+1G>C (de novo) | — | Intron 9 | Non‐coding | Pathogenic (PVS1, PM2, PS2) | 32 | AD | Dysmorphic
      facial findings, microcephaly, DD, cutaneous syndactyly on foot
    explanation: >-
      Table 1 provides the pathogenic classification and de novo status.
  clinical_significance: PATHOGENIC
- name: NM_182641.4:c.6022G>A (p.Val2008Ile)
  gene:
    preferred_term: BPTF
    term:
      id: hgnc:3581
      label: BPTF
  variant_type: single nucleotide variant
  description: >-
    Paternally inherited missense VUS in the 2025 series. The father was not clinically examined in detail;
    this observation does not establish pathogenicity, penetrance or a missense-specific severity relationship.
  evidence:
  - reference: PMID:40415676
    reference_title: Effects of the Missense Variants on Complete Phenotype and Splicing Variant on Severe Growth Retardation in the BPTF Gene.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      c.6022G>A (paternal) | p.Val2008Ile | 17 | Missense | VUS (PM2, PP2) | 24.1 | AD | Dysmorphic facial
      findings, microcephaly ID/DD, speech delay, scoliosis, clinodactyly, small hands, pes planus
    explanation: >-
      The source table explicitly labels this variant VUS.
  clinical_significance: UNCERTAIN_SIGNIFICANCE
- name: NM_182641.4:c.6416G>A (p.Arg2139His)
  gene:
    preferred_term: BPTF
    term:
      id: hgnc:3581
      label: BPTF
  variant_type: single nucleotide variant
  description: >-
    Maternally inherited missense VUS reported in a daughter and mother. The mother had reported intellectual
    disability and hand findings but did not attend for detailed examination. Pathogenicity remains uncertain.
  evidence:
  - reference: PMID:40415676
    reference_title: Effects of the Missense Variants on Complete Phenotype and Splicing Variant on Severe Growth Retardation in the BPTF Gene.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "In Case #3, WES also detected the variant NM_182641.4: c.6416G>A: p.Arg2139His in the BPTF gene. This variant was inherited from the mother."
    explanation: >-
      Identifies the variant and segregation.
  - reference: PMID:40415676
    reference_title: Effects of the Missense Variants on Complete Phenotype and Splicing Variant on Severe Growth Retardation in the BPTF Gene.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      This change, p.Arg2139His, is classified as uncertain significance (PM2, PP2) in silico variant
      analysis databases according to the ACMG.
    explanation: >-
      Preserves the explicit uncertain classification.
  clinical_significance: UNCERTAIN_SIGNIFICANCE

📚

References & Deep Research

References

5

PMID:28942966

Haploinsufficiency of the Chromatin Remodeler BPTF Causes Syndromic Developmental and Speech Delay, Postnatal Microcephaly, and Dysmorphic Features.

No top-level findings curated for this source.

PMID:33522091

Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies.

No top-level findings curated for this source.

PMID:36153657

The effect of growth hormone treatment in children with novel BPTF gene variants: A report of two cases and literature review.

No top-level findings curated for this source.

PMID:41213919

Pathogenic variants in SMARCA1 cause an X-linked neurodevelopmental disorder modulated by NURF complex composition.

No top-level findings curated for this source.

url:https://pmc.ncbi.nlm.nih.gov/articles/PMC9558838/

Generation of a mouse model of the neurodevelopmental disorder with dysmorphic facies and distal limb anomalies syndrome - PMC

No top-level findings curated for this source.

Deep Research

1

Deep research results are used as seeds for research; they do not undergo the same validation as the main records and may contain errors. How we use deep research.

Evaluations and curation notes (1)

Create: BPTF-Related Neurodevelopmental Disorder (NEDDFL) · 2026-08-17T02:09:57Z · View source

New Mendelian entry for neurodevelopmental disorder with dysmorphic facies and distal limb anomalies (NEDDFL; MONDO:0060596, OMIM:617755, BPTF hgnc:3581), resolving issue #8533. NEC preflight (mandatory for this high-risk numbered NDD series): `runoak -i sqlite:obo:mondo info MONDO:0060596 -O obo` returned relationship RO:0004003 HGNC:3581 ! BPTF and xref OMIM:617755, confirming gene and OMIM identity before any deep-research content was used. Three confusable neighbours are recorded as differential_diagnoses: MONDO:0032855 (NEDDFSA, ZMIZ1 - a one-word label difference), MONDO:0044319 (IDDFSDA, OTUD6B - autosomal recessive; the reciprocal guardrail in that entry is honoured and no OTUD6B-specific citation is used anywhere here), and Silver-Russell syndrome (clinical phenocopy). PMID:33522091 is used extensively here; the OTUD6B entry deliberately excludes it precisely because it describes this BPTF entity. Deep research: Falcon (Edison Scientific) run, 21 citations, 5/5 references verified, 0 percent provider-reported confabulation rate. It agreed with the primary literature read independently and introduced no PMID not already cited, so it was used as corroboration only. No GeneReviews chapter exists for BPTF or NEDDFL (PubMed searched), so that baseline step does not apply. Mechanism: eight pathophysiology nodes, each tagged with biological_scale, running BPTF haploinsufficiency (MOLECULAR) -> impaired NURF chromatin remodeling (MOLECULAR) -> dysregulated developmental gene transcription (MOLECULAR) -> neural progenitor cell-cycle prolongation and apoptosis (CELLULAR) -> cortical hypoplasia and disrupted lamination (TISSUE), with a parallel PROVISIONAL craniofacial/limb patterning node (TISSUE) and two ORGANISM outputs (postnatal microcephaly with growth restriction; neurodevelopmental impairment). Two discussions record the open problems honestly: a KNOWLEDGE_GAP on why BPTF loss causes microcephaly while loss of Smarca1, its NURF ATPase partner, causes brain overgrowth; and a HUMAN_MODEL_MISMATCH on the principal mouse model being a homozygous conditional null while the human disease is heterozygous haploinsufficiency with near-silent heterozygous mice. Frequency discipline: bands are sourced from PMID:33522091 (26-individual expansion cohort) with verbatim quoted fractions. The larger pooled 38-case table in PMID:36153657 is recorded in prose only and is NOT used as an evidence snippet, because the reference validator can verify only that paper's abstract and the table is in the article body; the single band resting on that paper (short stature, 35 percent) uses a sentence that is in its abstract. Bands were omitted wherever no usable denominator exists. Term binding: the supportive-care and genetic-counseling treatments use NCIT:C15747 and NCIT:C15240 rather than the MAXO terms suggested in CLAUDE.md (MAXO:0000950, MAXO:0000079), because MAXO is not reachable from the NCIT:C25218 root of the TreatmentActionTerm dynamic enum and fails term validation. The same substitution is documented in the Progressive_Familial_Intrahepatic_Cholestasis entry, and a term-binding note in this entry warns reviewers not to revert it. Validation, run from inside the curation worktree: `just validate` passes all three stages (schema, terms, references); `just validate-references` reports 80/80 snippets verified against cached references; `just validate-terms` passes. Ten references were fetched with `just fetch-reference` (PMIDs 28942966, 33522091, 30633344, 35604347, 36153657, 38936258, 40614698, 40415676, 16728976, 18974875). PMID:30633344 has no retrievable abstract, so it is cited in prose only with no evidence snippet attached.

Falcon ▸

BPTF-Related Neurodevelopmental Disorder: Comprehensive Disease-Characteristics Report

Edison Scientific Literature 21 citations 2026-08-15T08:40:47.422885

BPTF-Related Neurodevelopmental Disorder: Comprehensive Disease-Characteristics Report

Executive summary and evidence limits

BPTF-related neurodevelopmental disorder is a rare Mendelian chromatin-remodeling disorder, conventionally named neurodevelopmental disorder with dysmorphic facies and distal limb anomalies (NEDDFL). It results primarily from heterozygous loss-of-function variants in BPTF and is best understood as an autosomal-dominant haploinsufficiency disorder. Developmental/intellectual disability, speech-language delay, postnatal microcephaly, and recognizable but variable dysmorphism form the core phenotype; motor delay, hypotonia, growth impairment, seizures, mild brain abnormalities, ophthalmologic findings, scoliosis, and distal-limb anomalies broaden the spectrum. The evidence base remains small: the landmark 2017 study described ten unrelated individuals, and the major 2021 expansion reported approximately 25–26 affected individuals with 20 distinct variants. Consequently, frequencies below are cohort proportions—not population estimates—and are vulnerable to referral and ascertainment bias. (glinton2021phenotypicexpansionof pages 1-3, stankiewicz2017haploinsufficiencyofthe pages 1-2, glinton2021phenotypicexpansionof pages 3-4)

Recent disease-specific literature is sparse. Important 2023 and 2024 reports concern growth-hormone use and epilepsy, respectively, but their full text was unavailable in the retrieved corpus; they are therefore flagged without extrapolating outcomes. No disease-specific interventional trial was identified. The strongest mechanistic development is the 2022 forebrain-specific mouse model and its RNA-sequencing analysis. (zapata2022generationofa pages 1-2)

1. Disease information

Definition and nomenclature

Preferred name: BPTF-related neurodevelopmental disorder.
Established alternative name: neurodevelopmental disorder with dysmorphic facies and distal limb anomalies.
Abbreviation: NEDDFL.
Category: Mendelian, syndromic neurodevelopmental disorder/chromatinopathy.

The 2021 abstract defines NEDDFL as being “defined primarily by developmental delay/intellectual disability, speech delay, postnatal microcephaly, and dysmorphic features” and resulting from heterozygous variants in dosage-sensitive BPTF. (glinton2021phenotypicexpansionof pages 1-3)

Identifiers

OMIM phenotype: 617755, NEDDFL.
Gene/locus: BPTF, chromosome 17q24.2.
MONDO: a disease-specific MONDO accession could not be verified from the retrieved primary literature; do not assign one without direct MONDO lookup.
Orphanet: no disease-specific Orpha code was verified.
ICD-10/ICD-11 and MeSH: no specific code/descriptor was identified. Coding generally requires broader categories for developmental/intellectual disability, microcephaly, epilepsy, or congenital malformations.

The source data are aggregated disease-level data from published case series and experimental studies, not an EHR-derived natural-history cohort. Individual-patient observations underlie the aggregate proportions. (stankiewicz2017haploinsufficiencyofthe pages 1-2, glinton2021phenotypicexpansionof pages 3-4)

2. Etiology

Causal factor

The primary cause is a heterozygous germline pathogenic variant or deletion affecting BPTF. The leading mechanism is reduced dosage—haploinsufficiency—rather than infection, toxin exposure, autoimmunity, or a metabolic enzyme defect. The 2017 cohort contained eight loss-of-function and two missense variants; the expanded cohort was dominated by frameshift, nonsense, splice, and exon-level loss variants. (glinton2021phenotypicexpansionof pages 3-4, stankiewicz2017haploinsufficiencyofthe pages 1-2)

Genetic risk

A pathogenic BPTF allele is itself the principal risk factor. Most initially reported variants were de novo, but the 2021 study documented four inherited changes, including transmission from non-mosaic affected parents, demonstrating vertical autosomal-dominant transmission and variable expressivity. (glinton2021phenotypicexpansionof pages 3-4)

No validated modifier gene, susceptibility locus, protective allele, founder mutation, ancestry enrichment, or carrier-frequency estimate is established. Missense and some inherited variants have been associated with milder presentations, but this is not yet a validated genotype–phenotype rule. (glinton2021phenotypicexpansionof pages 12-13, glinton2021phenotypicexpansionof pages 3-4)

Environmental and protective factors

No causal environmental, occupational, lifestyle, dietary, or infectious exposure has been demonstrated. No genetic or environmental protective factor has been reported. There is likewise no disease-specific gene–environment interaction literature. These are evidence gaps, not evidence that environmental influences can never affect clinical functioning.

3. Phenotypes

The most reproducible phenotype data are summarized below. Differences between quoted frequencies reflect different denominators, missing data, and whether the calculation concerned the novel cohort or all available individuals.

Neurodevelopmental and neurologic features

Developmental delay/intellectual disability: 10/10 in the 2017 cohort and approximately 88% in the 2021 expanded cohort. Severity is variable; onset is infancy/childhood and impairment is generally chronic. Suggested terms: HP:0001263 Global developmental delay, HP:0001249 Intellectual disability. (stankiewicz2017haploinsufficiencyofthe pages 1-2, glinton2021phenotypicexpansionof pages 3-4)
Speech-language delay: 10/10 in 2017 and approximately 85% in 2021. This is among the most consistent, functionally important manifestations. Suggested term: HP:0000750 Delayed speech and language development. (stankiewicz2017haploinsufficiencyofthe pages 1-2, glinton2021phenotypicexpansionof pages 3-4)
Motor delay: approximately 69% in the expanded cohort. Suggested term: HP:0001270 Motor delay. (glinton2021phenotypicexpansionof pages 3-4)
Hypotonia: history in approximately 38%. Suggested term: HP:0001252 Hypotonia. (glinton2021phenotypicexpansionof pages 4-5)
Microcephaly: postnatal microcephaly occurred in 7/9 in 2017. The expanded-study extractions report 42% in one denominator and 60% at assessment in another, while 40% had microcephaly at birth. The safest conclusion is that microcephaly is common but neither universal nor always strictly postnatal. Suggested terms: HP:0000252 Microcephaly and, only where serial measurements document it, HP:0000253 Progressive microcephaly. (stankiewicz2017haploinsufficiencyofthe pages 1-2, glinton2021phenotypicexpansionof pages 4-5)
Seizures/EEG abnormalities: six expanded-cohort participants had a seizure history requiring treatment; two additional individuals had electrographic abnormalities without reported clinical seizures. Suggested terms: HP:0001250 Seizure, HP:0010843 Abnormality of the EEG. (glinton2021phenotypicexpansionof pages 4-5)
Brain MRI: among 13 imaged individuals, 8 MRIs were normal and 5 showed mild structural abnormalities. Thus, a normal MRI does not exclude the disorder. Suggested term: HP:0410263 Abnormal brain MRI when applicable. (glinton2021phenotypicexpansionof pages 4-5)

Growth, craniofacial, skeletal, and ocular features

Short stature: approximately 25%; decreased weight/poor weight gain: approximately 53%. Suggested terms: HP:0004322 Short stature, HP:0004325 Decreased body weight/Poor weight gain, with exact HPO chosen to match the measured phenotype. (glinton2021phenotypicexpansionof pages 4-5)
Dysmorphism: 9/10 in 2017; 77% in one 2021 aggregate, while all 20 individuals with detailed available dysmorphology data had mild dysmorphism. Recurrent descriptions include a prominent nasal ridge, bulbous nasal tip, and pointed chin. Suggested umbrella term: HP:0001999 Facial dysmorphism, supplemented by feature-specific terms. (stankiewicz2017haploinsufficiencyofthe pages 1-2, glinton2021phenotypicexpansionof pages 4-5, glinton2021phenotypicexpansionof pages 9-10)
Distal-limb/skeletal abnormalities: cutaneous syndactyly, sandal gap, limb-length discrepancy, delayed bone age, and scoliosis occur variably. Suggested terms include HP:0001159 Syndactyly and HP:0002650 Scoliosis. (glinton2021phenotypicexpansionof pages 9-10, glinton2021phenotypicexpansionof pages 1-3)
Ophthalmologic complications: reported as an expanded component of the phenotype, but precise frequencies and diagnoses were unavailable in the extracted evidence. Use HP:0000478 Abnormality of the eye only as a parent term pending patient-specific coding. (glinton2021phenotypicexpansionof pages 1-3)

Behavioral, laboratory, and quality-of-life data

No consistent disease-specific psychiatric or behavioral profile, biochemical laboratory signature, validated patient-reported outcome, EQ-5D/SF-36 dataset, or formal quality-of-life study was identified. Nevertheless, cognitive, speech, motor, seizure, and visual impairments predict substantial effects on communication, education, independence, and caregiver burden. That functional interpretation is clinically reasonable but has not been quantified specifically for NEDDFL.

4. Genetic and molecular information

Gene and variant spectrum

BPTF encodes bromodomain PHD finger transcription factor, the largest subunit of the nucleosome-remodeling factor (NURF) complex. In 2017, ten unrelated individuals carried eight loss-of-function and two missense variants; eight variants were confirmed de novo and two had unresolved parental origin. (stankiewicz2017haploinsufficiencyofthe pages 1-2)

The expanded study reported 20 distinct variants: 9 frameshift, 4 nonsense, 3 splice, 2 in-frame deletion, 1 missense, and 1 single-exon deletion. Reported ACMG classifications were 11 pathogenic, 7 likely pathogenic, and 2 VUS. Four causative changes were inherited and fourteen were de novo in the available summary. Appropriate Sequence Ontology classes include frameshift_variant, stop_gained, splice_donor_variant, splice_acceptor_variant, inframe_deletion, missense_variant, and exon_loss_variant. (glinton2021phenotypicexpansionof pages 3-4)

Variants are germline in the constitutional disorder. Somatic BPTF alterations studied in cancer should not be conflated with NEDDFL. Population frequencies were not available in the retrieved evidence; pathogenic loss-of-function variants are expected to be very rare, but every candidate requires direct gnomAD/ClinVar evaluation using its exact HGVS expression.

Functional consequence and epigenetics

The best-supported consequence is loss of function and haploinsufficiency. BPTF recognizes H3K4me3 through its PHD finger and H4K16ac through its bromodomain, helping recruit/position the NURF ATP-dependent remodeling machinery at chromatin. The disorder is therefore an epigenetic chromatin-remodeling disease, although no validated diagnostic DNA-methylation episignature was identified. (glinton2021phenotypicexpansionof pages 1-3)

No dominant-negative or gain-of-function disease mechanism, modifier gene, or reproducible human methylomic signature has been established. Large deletions involving 17q24.2 may produce broader contiguous-gene phenotypes and require CNV interpretation rather than automatic attribution solely to BPTF.

5. Environmental information

No toxin, radiation, pollution, occupational exposure, smoking, diet, alcohol, exercise pattern, or infectious agent is known to cause or trigger this Mendelian disorder. Lifestyle measures remain relevant to general health and management of secondary complications but are not primary prevention for a pathogenic germline BPTF variant. There is no zoonotic or transmissible component.

6. Mechanism and pathophysiology

Causal chain

The most defensible causal model is:

Upstream genetic lesion: heterozygous BPTF loss-of-function/deletion lowers functional BPTF dosage.
Chromatin-level defect: impaired NURF targeting/remodeling alters nucleosome positioning and transcriptional accessibility at developmentally regulated loci.
Neural-progenitor consequences: altered fate-determining transcription factors, prolonged progenitor cell cycle, and increased apoptosis reduce neuronal output.
Corticogenesis defect: impaired neuronal maturation and specification, reduced deep-layer neurons, and disrupted cortical lamination produce cortical hypoplasia.
Clinical manifestations: impaired cortical growth and circuit development plausibly generate microcephaly, developmental/intellectual disability, speech delay, motor impairment, and seizure susceptibility. (glinton2021phenotypicexpansionof pages 1-3, zapata2022generationofa pages 1-2)

In the 2022 mouse study, forebrain-specific Bptf loss produced “severe cortical hypoplasia”; prolonged progenitor cycling and high cell death reduced neuronal output, while lamination and acquisition of neuronal identities such as CTIP2-positive fates were impaired. RNA-seq showed dysregulation of fate-determining transcription factors and pathways involving neural development, apoptotic signaling, and amino-acid biosynthesis; dysregulated genes were enriched for MYC-binding sites, consistent with BPTF–MYC transcriptional cooperation. (zapata2022generationofa pages 1-2)

Suggested functional ontology

GO:0006338 chromatin remodeling
GO:0042393 histone binding
GO:0006357 regulation of transcription by RNA polymerase II
GO:0022008 neurogenesis
GO:0007399 nervous system development
GO:0006915 apoptotic process
GO:0051301 cell division
GO:0008652 cellular amino-acid biosynthetic process
GO:0005634 nucleus
GO:0000785 chromatin

Suggested cell annotations are neural progenitor cell, radial glial/neural stem cell, cortical projection neuron, deep-layer cortical neuron, and generic neuron (CL:0000540); subtype accessions should be checked against the current Cell Ontology release.

Molecular profiling and advanced technologies

Disease-relevant molecular profiling currently consists principally of mouse forebrain bulk RNA-seq. No robust human patient-brain transcriptome, proteome, metabolome, lipidome, single-cell atlas, spatial-transcriptomic dataset, organoid study, or clinical multi-omics signature was identified. The 2021 clinical authors noted the absence of a well-validated functional assay and suggested RNA-seq or proteomics might help resolve difficult variants, particularly missense variants; this remains investigational rather than standard diagnosis. (glinton2021phenotypicexpansionof pages 12-13)

There is no evidence that immune dysregulation, chronic inflammation, ischemia, fibrosis, mitochondrial failure, or a discrete metabolic block is a primary mechanism. Altered amino-acid-biosynthesis pathways in knockout mouse RNA-seq are downstream expression findings, not proof of a treatable human metabolic deficiency. (zapata2022generationofa pages 1-2)

7. Anatomical structures affected

The principal organ system is the central nervous system, especially the developing forebrain/cerebral cortex. Suggested anatomy terms include UBERON:0000955 brain, UBERON:0001890 cerebral cortex, and a current UBERON term for telencephalon/forebrain. Human imaging can be normal or show mild abnormalities, whereas complete forebrain-specific knockout in mice produces marked cortical hypoplasia. (zapata2022generationofa pages 1-2, glinton2021phenotypicexpansionof pages 4-5)

Secondary systems include craniofacial structures, distal limbs/skeleton, eyes, and general somatic growth. The relevant tissue is nervous tissue; implicated cells are neural progenitors and differentiating/mature cortical neurons. The main subcellular compartment is nuclear chromatin. Findings are not described as unilateral or lateralized.

8. Temporal development

The disorder is developmental, with congenital or early-childhood onset. Growth restriction or microcephaly may be present at birth, whereas some individuals develop postnatal microcephaly. Delayed milestones and language become evident in infancy or early childhood. (stankiewicz2017haploinsufficiencyofthe pages 1-2, glinton2021phenotypicexpansionof pages 4-5)

The course is chronic and lifelong rather than episodic or relapsing-remitting. Published ages extended from 23 months to 55 years in the expanded cohort, demonstrating adult survival. There is no validated staging system, progression rate, remission pattern, or defined end stage. Early childhood is likely the most important intervention window for speech, motor, educational, visual, and seizure services, but no study has quantified a critical therapeutic period. (glinton2021phenotypicexpansionof pages 3-4)

9. Inheritance and population

Inheritance is autosomal dominant. Most pathogenic variants arise de novo, although affected-parent transmission is established. When a parent carries the variant, the theoretical transmission probability is 50% per pregnancy; actual phenotype severity cannot be predicted reliably because expressivity is variable. For an apparently de novo variant, recurrence risk is low but not zero because parental germline mosaicism cannot be excluded by routine blood testing. (glinton2021phenotypicexpansionof pages 3-4)

Penetrance has not been quantified. Anticipation, founder effects, consanguinity effects, population-specific variants, and carrier frequency are not established. Both sexes are affected; one summary reported 14 males and 11 females, with no evidence for sex-linked inheritance. The published sample spans childhood through middle adulthood. (glinton2021phenotypicexpansionof pages 3-4)

No prevalence, incidence, geographic clustering, ancestry excess, or registry-derived epidemiologic estimate is available. It should be represented as an ultra-rare disorder of unknown prevalence rather than assigning a numerical rate.

10. Diagnostics

Recommended genomic approach

There are no formal NEDDFL diagnostic criteria. Diagnosis requires a compatible phenotype plus molecular confirmation.

First-line broad testing: trio exome sequencing or genome sequencing for unexplained syndromic developmental delay/intellectual disability, ideally with copy-number calling.
CNV testing: chromosomal microarray remains useful for exon/gene or larger 17q24.2 deletions and was used in foundational ascertainment. Genome sequencing may combine sequence and structural-variant detection.
Panel testing: a neurodevelopmental disorder/intellectual-disability or chromatinopathy panel should include BPTF and provide validated deletion/duplication analysis.
Single-gene testing: most appropriate when the phenotype is strongly suggestive or for familial segregation, prenatal diagnosis, and cascade testing.
Variant interpretation: apply ACMG/AMP criteria, parental testing, phenotype match, population frequency, predicted loss of function, transcript relevance, and CNV boundaries. A BPTF missense VUS alone does not establish diagnosis. (glinton2021phenotypicexpansionof pages 12-13, stankiewicz2017haploinsufficiencyofthe pages 1-2)

Karyotyping and FISH have low sensitivity for small sequence variants and are reserved for suspected large rearrangements or confirmation. Mitochondrial DNA and repeat-expansion testing are not disease-specific tests. RNA sequencing may help establish splice effects; proteomics and epigenomics remain investigational. (glinton2021phenotypicexpansionof pages 12-13)

Clinical evaluation after diagnosis

Recommended baseline assessment, extrapolated from the observed spectrum, includes detailed developmental/neuropsychological and speech-language evaluation; serial height, weight, and head circumference; neurologic examination; EEG for suspected seizures; brain MRI when neurologically indicated; ophthalmology; hearing assessment; musculoskeletal examination for scoliosis and limb anomalies; and review of feeding/nutrition. These are pragmatic surveillance recommendations, not evidence-based NEDDFL guidelines.

There is no blood, urine, enzyme, biopsy, metabolite, protein, or circulating biomarker diagnostic for the syndrome.

Differential diagnosis

Consider other chromatin-remodeling/chromatin-reader disorders, syndromic intellectual disability with microcephaly, copy-number syndromes involving 17q24, and growth disorders. Phenotypic overlap can include Silver–Russell syndrome: a cited adult with BPTF disruption was initially given that diagnosis. Distinction depends on genomic testing rather than facial gestalt alone. (glinton2021phenotypicexpansionof pages 13-13)

No newborn population screening or general-population carrier screening is available. Cascade testing is appropriate once a familial pathogenic variant is established.

11. Outcome and prognosis

No survival curve, disease-specific mortality rate, or life-expectancy estimate exists. Survival into adulthood—including an individual aged 55 years—has been documented, but the literature is too small to conclude that life expectancy is normal. (glinton2021phenotypicexpansionof pages 3-4)

Long-term morbidity is primarily neurodevelopmental and functional: communication limitations, intellectual disability, motor delay/hypotonia, epilepsy in a subset, growth impairment, ocular complications, and orthopedic issues. Recovery to a premorbid state is not expected because the condition reflects altered development; nevertheless, function can improve with therapy, education, communication supports, and control of secondary complications. No validated prognostic biomarker or genotype-based outcome calculator exists.

12. Treatment and real-world implementation

There is no approved disease-modifying, gene, RNA, cell, epigenetic, or targeted therapy for BPTF-related neurodevelopmental disorder. Management is individualized and multidisciplinary:

early developmental intervention and special education;
speech-language therapy, including augmentative and alternative communication where needed;
physical and occupational therapy for hypotonia, motor delay, mobility, and adaptive skills;
standard antiseizure treatment guided by seizure type and EEG;
ophthalmologic correction/treatment;
nutritional and feeding support;
orthopedic surveillance and treatment for scoliosis or limb-related functional problems;
psychosocial and family support.

Suggested NCIT concepts include Genetic Counseling, Supportive Care, Speech Therapy, Physical Therapy, Occupational Therapy, Anticonvulsant Therapy, and Vagus Nerve Stimulation; current NCIT identifiers should be validated during ingestion.

Case-level antiseizure implementations in the 2021 cohort included sodium valproate, levetiracetam, and a vagal nerve stimulator. These observations show real-world use but do not establish comparative efficacy or syndrome-specific response rates. (glinton2021phenotypicexpansionof pages 4-5)

A 2023 publication, Wu and Chen, “The effect of growth hormone treatment in children with novel BPTF gene variants: a report of two cases and literature review,” Molecular Genetics & Genomic Medicine, DOI 10.1002/mgg3.2066, was identified. Because direct outcome data were unavailable in the retrieved evidence, growth hormone should not be portrayed as established NEDDFL therapy; its use would require conventional endocrinologic evaluation and individualized risk–benefit review.

A 2024 epilepsy-focused report, Ferretti et al., “Epilepsy as a novel phenotype of BPTF-related disorders,” Pediatric Neurology, DOI 10.1016/j.pediatrneurol.2024.06.001, indicates growing characterization of seizure phenotypes, but detailed statistics could not be verified here.

No BPTF/NEDDFL-specific interventional ClinicalTrials.gov study or treatment algorithm was identified. Pharmacogenomic guidance specific to BPTF is absent.

13. Prevention

There is no lifestyle, medication, vaccine, or environmental intervention that prevents a de novo pathogenic BPTF variant. Primary prevention is therefore limited to informed reproductive options when a familial variant is known: genetic counseling, prenatal diagnosis, and preimplantation genetic testing for monogenic disease. Secondary prevention consists of early molecular diagnosis and prompt developmental, communication, vision, nutritional, orthopedic, and epilepsy evaluation. Tertiary prevention aims to reduce complications and maximize function through ongoing multidisciplinary care.

For confirmed de novo cases, parental testing informs recurrence counseling but cannot eliminate residual germline-mosaicism risk. For inherited variants, cascade testing can identify relatives who may benefit from clinical evaluation and reproductive counseling. (glinton2021phenotypicexpansionof pages 3-4)

14. Other species and natural disease

No naturally occurring BPTF-associated veterinary disease, affected breed, zoonotic potential, or cross-species transmission was identified. Orthologous developmental function is conserved experimentally in vertebrates. Relevant taxa are Danio rerio (NCBI Taxonomy 7955) and Mus musculus (NCBI Taxonomy 10090). Species-specific Bptf gene identifiers should be obtained directly from the current NCBI Gene/Alliance records before database ingestion.

15. Model organisms

Zebrafish

CRISPR-Cas9 disruption of bptf in F0 zebrafish caused reduced head size, increased TUNEL-positive apoptosis, altered phospho-histone-H3 proliferation measures, and abnormal craniofacial patterning, including increased ceratohyal angle. This recapitulates the human microcephaly/craniofacial axis and supports a developmental loss-of-function mechanism. Limitations include F0 mosaicism, uncertain allele dosage, and incomplete modeling of cognition and speech. (stankiewicz2017haploinsufficiencyofthe pages 1-2)

Mouse

The 2022 Emx1-Cre forebrain-specific Bptf conditional knockout survived into adulthood but was smaller and had severe cortical hypoplasia, prolonged progenitor cycling, increased cell death, reduced neuronal output, disturbed lamination, fewer deep-layer neurons, and impaired neuronal maturation. It is a strong mechanistic model for corticogenesis and transcriptomic studies. Its major limitation is that biallelic tissue-specific ablation is more severe and spatially restricted than constitutional human heterozygous haploinsufficiency; heterozygous mice reportedly had much smaller effects. (glinton2021phenotypicexpansionof pages 1-3, zapata2022generationofa pages 1-2)

No validated patient-derived iPSC, brain-organoid, rat, Drosophila, C. elegans, or naturally occurring animal model was identified in the retrieved disease-specific evidence.

Recent research and authoritative interpretation

The field’s current interpretation is that BPTF-related NDD belongs to the broader class of dosage-sensitive chromatinopathies. Human genetics strongly supports haploinsufficiency, while zebrafish and mouse experiments connect the genetic lesion to apoptosis, progenitor dysfunction, reduced neuronal production, and impaired cortical fate specification. The major unresolved translational challenge is that the severe knockout models do not precisely reproduce the variable heterozygous human phenotype. Human cellular models and variant-sensitive functional assays are priorities, particularly for missense and inherited variants. (zapata2022generationofa pages 1-2, glinton2021phenotypicexpansionof pages 12-13)

The most important recent developments are therefore phenotypic rather than therapeutic: recognition of inherited disease and milder expression, expanded seizure and ophthalmologic phenotypes, exploratory growth-hormone treatment, and mechanistic forebrain RNA-seq. No precision therapy has reached clinical implementation.

Key primary sources and abstract quotations

Stankiewicz et al. “Haploinsufficiency of the Chromatin Remodeler BPTF Causes Syndromic Developmental and Speech Delay, Postnatal Microcephaly, and Dysmorphic Features.” American Journal of Human Genetics 101:503–515. Published October 2017. DOI: 10.1016/j.ajhg.2017.08.014. Landmark human cohort plus zebrafish validation: ten unrelated individuals, 8 loss-of-function and 2 missense variants, with DD/ID and speech delay in 10/10. (stankiewicz2017haploinsufficiencyofthe pages 1-2)
Glinton et al. “Phenotypic expansion of the BPTF-related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies.” American Journal of Medical Genetics Part A 185:1366–1378. Published January 2021. DOI: 10.1002/ajmg.a.62102. Abstract quotation: “To expand the NEDDFL phenotypic spectrum, we describe the clinical features in 25 novel individuals with 20 distinct, clinically relevant variants in BPTF, including four individuals with inherited changes in BPTF.” It further reports “mild brain abnormalities, seizures, scoliosis, and a variety of ophthalmologic complications.” (glinton2021phenotypicexpansionof pages 1-3)
Zapata, Yan, and Picketts. “Generation of a mouse model of the neurodevelopmental disorder with dysmorphic facies and distal limb anomalies (NEDDFL) syndrome.” Human Molecular Genetics 31:3405–3421. Published May 2022. DOI: 10.1093/hmg/ddac119. Abstract quotation: “Prolonged progenitor cell cycle length and a high incidence of cell death reduced neuronal output.” The authors also report disrupted cortical lamination, neuronal maturation defects, and RNA-seq pathway changes. (zapata2022generationofa pages 1-2)

Knowledge-base-ready summary

The following artifact consolidates evidence-supported disease, phenotype, mechanism, diagnostic, treatment, anatomy, and model annotations, while explicitly marking unverified identifiers and unknown fields.

domain	evidence-based finding	suggested ontology terms	evidence strength/limitations
Disease name/definition	BPTF-related neurodevelopmental disorder is also called neurodevelopmental disorder with dysmorphic facies and distal limb anomalies (NEDDFL); core syndrome includes developmental delay/intellectual disability, speech delay, postnatal microcephaly, and dysmorphic features due to heterozygous BPTF variants (glinton2021phenotypicexpansionof pages 1-3, stankiewicz2017haploinsufficiencyofthe pages 1-2)	OMIM:617755; MONDO: not verified/uncertain; disease label: NEDDFL	Strong human cohort evidence from 2017 and 2021; MONDO/Orphanet identifier not verified in available evidence
Synonyms	BPTF-related neurodevelopmental disorder; NEDDFL; neurodevelopmental disorder with dysmorphic facies and distal limb anomalies (glinton2021phenotypicexpansionof pages 1-3, zapata2022generationofa pages 1-2)	Exact synonym mapping pending external ontology verification	Strong for naming in literature; formal synonym list incomplete in available context
Evidence source type	Data are aggregated from published human case series/cohorts and model-organism studies, not EHR-derived datasets in the available evidence (stankiewicz2017haploinsufficiencyofthe pages 1-2, zapata2022generationofa pages 1-2)	ECO:0000218 expert assertion supported by traceable author statement (suggested)	Strong for published-source provenance; no registry-scale natural history dataset identified
Causal gene/locus	Causal gene is BPTF on chromosome 17q24.2; disease is associated with heterozygous pathogenic variants and haploinsufficiency (stankiewicz2017haploinsufficiencyofthe pages 1-2)	HGNC:BPTF; UBERON not applicable; Sequence Ontology terms: frameshift_variant, stop_gained, splice_acceptor_variant/splice_donor_variant, inframe_deletion, missense_variant	Strong for gene-disease validity; exact HGNC ID not provided in available context
Protein/complex	BPTF is the largest subunit of the nucleosome remodeling factor (NURF) chromatin-remodeling complex (glinton2021phenotypicexpansionof pages 1-3, zapata2022generationofa pages 1-2)	GO:0006338 chromatin remodeling; GO:0030674 protein-containing complex (general); NURF complex term suggested if curated externally	Strong mechanistic consensus; exact GO complex accession for NURF not verified here
Molecular mechanism	Current best-supported mechanism is BPTF haploinsufficiency causing dysregulated chromatin remodeling and transcription during neurodevelopment (glinton2021phenotypicexpansionof pages 1-3, glinton2021phenotypicexpansionof pages 3-4, stankiewicz2017haploinsufficiencyofthe pages 1-2, zapata2022generationofa pages 1-2)	HP:0000006 Autosomal dominant inheritance; GO:0006357 regulation of transcription by RNA polymerase II; GO:0006338 chromatin remodeling	Strong for loss-of-function/haploinsufficiency; no evidence for protective variants or environmental triggers
Chromatin-reader biology	BPTF binds H3K4me3 through its PHD finger and H4K16ac through its bromodomain, supporting an epigenetic reader/remodeler role (glinton2021phenotypicexpansionof pages 1-3)	GO:0042393 histone binding; GO:0016568 chromatin modification (broad); CHEBI terms for modified histones could be added in curation	Moderate-strong mechanistic evidence; largely inferred from molecular studies summarized in clinical paper
Core phenotype: developmental delay/intellectual disability	Reported in 10/10 individuals in the 2017 cohort and 88% in the 2021 cohort (stankiewicz2017haploinsufficiencyofthe pages 1-2, glinton2021phenotypicexpansionof pages 3-4)	HP:0001263 Global developmental delay; HP:0001249 Intellectual disability	Strong replicated cohort evidence; severity spectrum incompletely quantified
Core phenotype: speech delay	Reported in 10/10 individuals in 2017 and 85% in 2021 (stankiewicz2017haploinsufficiencyofthe pages 1-2, glinton2021phenotypicexpansionof pages 3-4)	HP:0000750 Delayed speech and language development	Strong replicated cohort evidence
Core phenotype: postnatal microcephaly	Reported in 7/9 individuals in 2017; 42% in 2021 cohort summary; 60% microcephaly at assessment in one detailed 2021 extraction; 40% had microcephaly at birth in that extraction (stankiewicz2017haploinsufficiencyofthe pages 1-2, glinton2021phenotypicexpansionof pages 3-4, glinton2021phenotypicexpansionof pages 4-5)	HP:0000252 Microcephaly; HP:0000253 Progressive microcephaly (suggested where postnatal worsening documented)	Strong that microcephaly is common; exact frequency varies with denominator/definition across summaries
Core phenotype: dysmorphic features	Dysmorphic features were present in 9/10 in 2017 and 77% in one 2021 summary; all 20 individuals with available detailed dysmorphology data reportedly had mild dysmorphic features in another 2021 extraction (stankiewicz2017haploinsufficiencyofthe pages 1-2, glinton2021phenotypicexpansionof pages 3-4, glinton2021phenotypicexpansionof pages 4-5)	HP:0001999 Facial dysmorphism; phenotype-specific HPOs may include pointed chin, bulbous nose, prominent nasal ridge	Strong that dysmorphism is common; exact aggregate frequency varies by denominator and ascertainment
Core phenotype: motor delay	Motor delay reported in 69% of 2021 cohort (glinton2021phenotypicexpansionof pages 3-4)	HP:0001270 Motor delay	Moderate-strong; not explicitly quantified in 2017 extraction
Core phenotype: hypotonia	Hypotonia/history of hypotonia reported in 38% of 2021 cohort (glinton2021phenotypicexpansionof pages 3-4, glinton2021phenotypicexpansionof pages 4-5)	HP:0001252 Hypotonia	Moderate-strong cohort evidence
Additional neurologic phenotype: seizures/EEG abnormalities	Seizures/EEG abnormalities were newly emphasized in 2021; 6 patients had seizure history requiring treatment, and 2 had electrographic abnormalities only (glinton2021phenotypicexpansionof pages 4-5, glinton2021phenotypicexpansionof pages 1-3)	HP:0001250 Seizure; HP:0010843 Abnormality of the EEG	Moderate evidence from expanded cohort; 2024 epilepsy-focused paper identified bibliographically but not available in accessible full text
Neuroimaging	In 2021, MRI was normal in 8/13 imaged individuals and mildly abnormal in 5/13, indicating variable and often subtle brain structural findings (glinton2021phenotypicexpansionof pages 4-5, glinton2021phenotypicexpansionof pages 1-3)	HP:0410263 Abnormal brain MRI; UBERON:0000955 brain	Moderate evidence; exact MRI anomaly types not fully extractable from available context
Skeletal/limb phenotype	Distal limb anomalies are part of the syndrome label; reported findings include scoliosis, cutaneous syndactyly, sandal-gap anomalies, limb-length discrepancy, and delayed bone age in some individuals (glinton2021phenotypicexpansionof pages 9-10, glinton2021phenotypicexpansionof pages 1-3)	HP:0001159 Syndactyly; HP:0002650 Scoliosis; HP:0010687 Abnormality of the digits	Moderate evidence; frequencies not fully extractable
Ophthalmologic phenotype	Ophthalmologic complications were reported in the expanded 2021 cohort (glinton2021phenotypicexpansionof pages 1-3)	HP:0000478 Abnormality of the eye	Moderate evidence; exact eye findings and frequencies not fully extractable
Growth phenotype	Short stature occurred in 25%, decreased weight in 53%, and microcephaly/growth restriction were also observed in 2021 extraction (glinton2021phenotypicexpansionof pages 4-5)	HP:0004322 Short stature; HP:0004325 Poor weight gain	Moderate evidence; 2023 growth-hormone report was identified bibliographically but direct outcome details were unavailable
Age at onset/course	Typical onset is congenital/early childhood with neurodevelopmental manifestations recognized in infancy or childhood; published ages ranged from 2.1-13 years in 2017 and 23 months-55 years in 2021, supporting lifelong persistence (stankiewicz2017haploinsufficiencyofthe pages 1-2, glinton2021phenotypicexpansionof pages 3-4)	HP:0003577 Congenital onset; HP:0011463 Childhood onset	Strong for pediatric onset and chronic course; no formal staging system identified
Variant spectrum	2017: 8 loss-of-function and 2 missense variants among 10 unrelated individuals. 2021: 20 distinct variants including 9 frameshift, 4 nonsense, 3 splicing, 2 in-frame deletions, 1 missense, and 1 single-exon deletion; ACMG classes included pathogenic, likely pathogenic, and 2 VUS (stankiewicz2017haploinsufficiencyofthe pages 1-2, glinton2021phenotypicexpansionof pages 3-4)	Sequence Ontology: frameshift_variant, stop_gained, splice_region/splice_donor/splice_acceptor, inframe_deletion, missense_variant, exon_loss_variant	Strong for predominance of truncating variants; exact HGVS list incomplete in accessible evidence
Inheritance	Predominantly autosomal dominant. Initial reports were mostly de novo; 2021 provided first non-mosaic affected-parent transmissions, showing inherited causative variants also occur (glinton2021phenotypicexpansionof pages 3-4, stankiewicz2017haploinsufficiencyofthe pages 1-2)	HP:0000006 Autosomal dominant inheritance; HP:0025352 De novo mutation (suggested annotation at variant level)	Strong for AD inheritance with variable expressivity; penetrance not quantified
Penetrance/expressivity	Expressivity appears variable, with milder phenotypes noted especially for some missense/inherited cases; penetrance remains not established from available data (glinton2021phenotypicexpansionof pages 12-13, glinton2021phenotypicexpansionof pages 3-4)	HP:0003828 Variable expressivity	Moderate evidence for variability; penetrance unknown
Population/epidemiology	No reliable prevalence or incidence estimates were identified in the available evidence; published literature consists of rare case series/families (stankiewicz2017haploinsufficiencyofthe pages 1-2, glinton2021phenotypicexpansionof pages 3-4)	Orphan disease; MONDO/Orphanet prevalence pending verification	Major evidence gap
Sex distribution	2021 cohort included 14 males and 11 females in the extracted summary, arguing against a strong sex-limited pattern (glinton2021phenotypicexpansionof pages 3-4)	PATO sex terms not necessary	Moderate evidence; one extracted count sums to 25 despite cohort described as 26, indicating source-summary inconsistency
Diagnostics: clinical	Diagnosis is suspected from syndromic NDD with speech delay, microcephaly, dysmorphic facies, and distal limb anomalies, with supportive MRI/EEG findings when present (glinton2021phenotypicexpansionof pages 1-3, glinton2021phenotypicexpansionof pages 4-5, stankiewicz2017haploinsufficiencyofthe pages 1-2)	HPO set above; NCIT:C159866 Genetic Testing (broad suggested term)	Strong for phenotype-guided suspicion; no formal consensus clinical criteria identified
Diagnostics: genetic testing	WES and chromosomal microarray were used in the landmark cohort; later cohorts identified sequence variants and single-exon deletions, supporting exome/genome sequencing plus CNV analysis as useful approaches (stankiewicz2017haploinsufficiencyofthe pages 1-2, glinton2021phenotypicexpansionof pages 4-5)	NCIT:C101294 Whole Exome Sequencing; NCIT:C63420 Comparative Genomic Hybridization/array-based CNV analysis (suggested broad mapping)	Strong practical evidence from case ascertainment; no disease-specific testing guideline located
Functional/omics diagnostics	2021 authors noted lack of well-validated functional assays and suggested RNA-seq or proteomics may have diagnostic utility for difficult variants such as missense changes (glinton2021phenotypicexpansionof pages 12-13)	NCIT:C153191 RNA Sequencing; NCIT:C20085 Proteomic Profiling (suggested)	Hypothesis-level/author opinion rather than established clinical standard
Differential diagnosis	Differential includes other syndromic neurodevelopmental disorders/chromatinopathies and cases initially labeled as other growth syndromes; one cited 2019 adult case had initially been diagnosed with Silver-Russell syndrome (glinton2021phenotypicexpansionof pages 13-13)	Broad category: chromatinopathy	Limited direct evidence in available context
Treatment/supportive care	No disease-modifying therapy is established. Reported management is supportive and symptom-directed: developmental therapies, educational support, seizure management, and routine multidisciplinary surveillance (inferred from seizure treatments and chronic NDD features) (glinton2021phenotypicexpansionof pages 4-5)	NCIT:C15604 Supportive Care; NCIT:C21072 Physical Therapy; NCIT:C17733 Occupational Therapy; NCIT:C12453 Speech Therapy	Moderate evidence for supportive approach; formal treatment algorithms absent
Seizure treatment examples	Reported anti-seizure interventions in 2021 cohort included sodium valproate, levetiracetam, and vagal nerve stimulator use in individual patients (glinton2021phenotypicexpansionof pages 4-5)	NCIT:C29511 Sodium Valproate; NCIT:C1570 Levetiracetam; NCIT:C99939 Vagus Nerve Stimulation	Case-level evidence only; no response rates or syndrome-specific efficacy data
Growth hormone	A 2023 report on growth hormone treatment in children with novel BPTF variants was identified bibliographically but not accessible in full text here, so efficacy/safety cannot be reliably summarized (from search history noted in conversation)	NCIT:C1772 Somatropin/Growth Hormone (if later curated)	Explicit evidence gap in accessible corpus
Prognosis/outcomes	Available evidence suggests a chronic lifelong neurodevelopmental disorder with survival into adulthood documented (age up to 55 years in 2021 cohort), but no formal survival, mortality, or quality-of-life statistics were identified (glinton2021phenotypicexpansionof pages 3-4)	ICF/quality-of-life terms could be added later	Major gap: no natural-history or mortality study found
Environmental factors	No established environmental, infectious, lifestyle, or protective factors were identified; disease is currently understood as primarily Mendelian/genetic (stankiewicz2017haploinsufficiencyofthe pages 1-2, zapata2022generationofa pages 1-2)	Not established	Strong negative statement based on absence in current literature context
Gene-environment interaction	No BPTF-specific gene-environment interaction data were identified (stankiewicz2017haploinsufficiencyofthe pages 1-2, zapata2022generationofa pages 1-2)	Not established	Evidence gap
Primary anatomy	Central nervous system/brain, especially forebrain and cerebral cortex, are the primary affected structures based on human phenotype and mouse modeling (zapata2022generationofa pages 1-2)	UBERON:0000955 brain; UBERON:0001890 cerebral cortex; UBERON:0001891 telencephalon/forebrain suggested	Strong convergent human/model evidence
Cell types implicated	Neural progenitor cells and cortical neurons are implicated; mouse data show prolonged progenitor cell cycle, reduced neuronal output, and impaired deep-layer neuron maturation including Ctip2+ neurons (zapata2022generationofa pages 1-2)	CL:0011115 neural progenitor cell (suggested); CL:0000540 neuron; CL:cortical neuron/deep-layer cortical projection neuron suggested	Strong model evidence; exact CL IDs for all cortical subtypes should be curator-verified
Cellular processes	Upstream defect involves impaired chromatin remodeling/transcriptional regulation; downstream effects include prolonged progenitor cell cycle, apoptosis, disrupted neuronal fate specification, cortical lamination defects, and reduced neuronal maturation (zapata2022generationofa pages 1-2)	GO:0006338 chromatin remodeling; GO:0051301 cell division; GO:0006915 apoptotic process; GO:0022008 neurogenesis; GO:0007417 central nervous system development; GO:0007399 nervous system development	Strong mouse mechanistic evidence; direct human tissue confirmation lacking
Subcellular localization	Disease mechanism is centered in the nucleus/chromatin compartment, consistent with a chromatin-remodeling transcription factor (glinton2021phenotypicexpansionof pages 1-3, zapata2022generationofa pages 1-2)	GO:0005634 nucleus; GO:0000785 chromatin	Strong general mechanistic inference
Molecular profiling	Mouse forebrain RNA-seq identified altered expression of fate-determining transcription factors and pathways related to neural development, apoptotic signaling, and amino acid biosynthesis; dysregulated genes were enriched for Myc binding sites (zapata2022generationofa pages 1-2)	GO:0009880 embryonic pattern specification; GO:0043066 negative regulation of apoptotic process/related apoptosis terms; GO:0008652 cellular amino acid biosynthetic process	Strong model evidence; no human transcriptomic signature established
Expert mechanistic interpretation	Available studies support a causal chain from BPTF loss-of-function to NURF dysfunction, altered chromatin accessibility/transcription in developing cortex, reduced progenitor fitness and neuronal specification, then microcephaly/intellectual disability/speech delay (glinton2021phenotypicexpansionof pages 1-3, zapata2022generationofa pages 1-2)	Pathway annotation can center on chromatin remodeling and corticogenesis	Strong synthesis from human genetics plus mouse model
Animal model: zebrafish	CRISPR/Cas9 F0 zebrafish bptf disruption caused reduced head size, increased apoptosis, altered proliferation, and abnormal craniofacial patterning (stankiewicz2017haploinsufficiencyofthe pages 1-2)	NCBITaxon:7955 Danio rerio	Strong experimental support for developmental role; F0 mosaic model limitations
Animal model: mouse	Forebrain-specific Bptf conditional knockout mice were viable to adulthood but smaller and showed severe cortical hypoplasia, prolonged progenitor cell cycle, high cell death, disrupted cortical lamination, reduced deep-layer neurons, and neuronal maturation defects (zapata2022generationofa pages 1-2)	NCBITaxon:10090 Mus musculus	Strong disease-relevant mechanistic model; conditional knockout is more severe than human heterozygous state
Natural disease in other species	No naturally occurring veterinary BPTF-related disorder was identified in available evidence (stankiewicz2017haploinsufficiencyofthe pages 1-2, zapata2022generationofa pages 1-2)	Not established	Evidence gap
Clinical trials	No disease-specific interventional clinical trials were identified in the available search results (clinical trial search in conversation)	Not established	Evidence gap
Prevention/genetic counseling	Prevention is limited to reproductive/genetic counseling, with recurrence risk depending on whether a variant is de novo or inherited from an affected parent; cascade testing may be relevant once a familial variant is known (glinton2021phenotypicexpansionof pages 3-4)	NCIT:C15280 Genetic Counseling	Moderate evidence from inheritance data; no formal counseling guideline identified
Unknown/not established fields	Prevalence, incidence, penetrance, founder effects, carrier frequency, environmental modifiers, protective factors, standardized diagnostic criteria, prognostic biomarkers, disease-specific QoL measures, and targeted molecular therapies are not established in the available evidence (stankiewicz2017haploinsufficiencyofthe pages 1-2, glinton2021phenotypicexpansionof pages 12-13, glinton2021phenotypicexpansionof pages 3-4)	Mark as unknown/not established in KB	Important to preserve as explicit negatives/gaps rather than infer unsupported claims

Table: This table summarizes knowledge-base-ready findings for BPTF-related neurodevelopmental disorder/NEDDFL, including core phenotypes, mechanism, diagnostics, inheritance, and model evidence. It also flags important unknowns and limitations where the available evidence is sparse or unverified.

Critical data gaps

The following should remain explicitly unknown/not established in a production knowledge base: disease-specific MONDO and Orphanet identifiers unless separately verified; prevalence and incidence; penetrance; ancestry or geographic effects; founder variants; quantitative quality of life; standardized diagnostic criteria; longitudinal natural history; life expectancy; prognostic biomarkers; validated episignature; human single-cell/spatial/multi-omics profiles; treatment response rates; and disease-modifying or preventive therapy. Apparent precision beyond the small published cohorts would be misleading.

References

(glinton2021phenotypicexpansionof pages 1-3): Kevin E. Glinton, Anna C. E. Hurst, Kevin M. Bowling, Ingrid Cristian, Devon Haynes, Dusit Adstamongkonkul, Oskar Schnappauf, David B. Beck, Carole Brewer, Aditi Shah Parikh, Deepali N. Shinde, Alan Donaldson, Ariel Brautbar, Saskia Koene, Arie van Haeringen, Amélie Piton, Yline Capri, Margherita Furlan, Elena Gardella, Rikke Steensbjerre Møller, Irma van de Beek, Linda Zuurbier, Phillis Lakeman, Allan Bayat, Julian Martinez, Rebecca Signer, Pernille M. Torring, Morten Buch Engelund, Karen W. Gripp, Louise Amlie‐Wolf, Lindsay B. Henderson, Alina T. Midro, Eugeniusz Tarasów, Beata Stasiewicz‐Jarocka, Diana Moskal‐Jasinska, Paul Vos, Felix Boschann, Corinna Stoltenburg, Oliver Puk, Inger‐Lise Mero, Kristine Lossius, Cyril Mignot, Boris Keren, Johanna C. Acosta Guio, Ignacio Briceño, Alberto Gomez, Yaping Yang, and Pawel Stankiewicz. Phenotypic expansion of the bptf‐related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies. American Journal of Medical Genetics. Part a, 185:1366-1378, Jan 2021. URL: https://doi.org/10.1002/ajmg.a.62102, doi:10.1002/ajmg.a.62102. This article has 33 citations and is from a peer-reviewed journal.
(stankiewicz2017haploinsufficiencyofthe pages 1-2): Paweł Stankiewicz, Tahir N. Khan, Przemyslaw Szafranski, Leah Slattery, Haley Streff, Francesco Vetrini, Jonathan A. Bernstein, Chester W. Brown, Jill A. Rosenfeld, Surya Rednam, Sarah Scollon, Katie L. Bergstrom, Donald W. Parsons, Sharon E. Plon, Marta W. Vieira, Caio R.D.C. Quaio, Wagner A.R. Baratela, Johanna C. Acosta Guio, Ruth Armstrong, Sarju G. Mehta, Patrick Rump, Rolph Pfundt, Raymond Lewandowski, Erica M. Fernandes, Deepali N. Shinde, Sha Tang, Juliane Hoyer, Christiane Zweier, André Reis, Carlos A. Bacino, Rui Xiao, Amy M. Breman, Janice L. Smith, Nicholas Katsanis, Bret Bostwick, Bernt Popp, Erica E. Davis, and Yaping Yang. Haploinsufficiency of the chromatin remodeler bptf causes syndromic developmental and speech delay, postnatal microcephaly, and dysmorphic features. American journal of human genetics, 101 4:503-515, Oct 2017. URL: https://doi.org/10.1016/j.ajhg.2017.08.014, doi:10.1016/j.ajhg.2017.08.014. This article has 113 citations and is from a highest quality peer-reviewed journal.
(glinton2021phenotypicexpansionof pages 3-4): Kevin E. Glinton, Anna C. E. Hurst, Kevin M. Bowling, Ingrid Cristian, Devon Haynes, Dusit Adstamongkonkul, Oskar Schnappauf, David B. Beck, Carole Brewer, Aditi Shah Parikh, Deepali N. Shinde, Alan Donaldson, Ariel Brautbar, Saskia Koene, Arie van Haeringen, Amélie Piton, Yline Capri, Margherita Furlan, Elena Gardella, Rikke Steensbjerre Møller, Irma van de Beek, Linda Zuurbier, Phillis Lakeman, Allan Bayat, Julian Martinez, Rebecca Signer, Pernille M. Torring, Morten Buch Engelund, Karen W. Gripp, Louise Amlie‐Wolf, Lindsay B. Henderson, Alina T. Midro, Eugeniusz Tarasów, Beata Stasiewicz‐Jarocka, Diana Moskal‐Jasinska, Paul Vos, Felix Boschann, Corinna Stoltenburg, Oliver Puk, Inger‐Lise Mero, Kristine Lossius, Cyril Mignot, Boris Keren, Johanna C. Acosta Guio, Ignacio Briceño, Alberto Gomez, Yaping Yang, and Pawel Stankiewicz. Phenotypic expansion of the bptf‐related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies. American Journal of Medical Genetics. Part a, 185:1366-1378, Jan 2021. URL: https://doi.org/10.1002/ajmg.a.62102, doi:10.1002/ajmg.a.62102. This article has 33 citations and is from a peer-reviewed journal.
(zapata2022generationofa pages 1-2): Gerardo Zapata, Keqin Yan, and David J Picketts. Generation of a mouse model of the neurodevelopmental disorder with dysmorphic facies and distal limb anomalies (neddfl) syndrome. Human molecular genetics, 31:3405-3421, May 2022. URL: https://doi.org/10.1093/hmg/ddac119, doi:10.1093/hmg/ddac119. This article has 14 citations and is from a domain leading peer-reviewed journal.
(glinton2021phenotypicexpansionof pages 12-13): Kevin E. Glinton, Anna C. E. Hurst, Kevin M. Bowling, Ingrid Cristian, Devon Haynes, Dusit Adstamongkonkul, Oskar Schnappauf, David B. Beck, Carole Brewer, Aditi Shah Parikh, Deepali N. Shinde, Alan Donaldson, Ariel Brautbar, Saskia Koene, Arie van Haeringen, Amélie Piton, Yline Capri, Margherita Furlan, Elena Gardella, Rikke Steensbjerre Møller, Irma van de Beek, Linda Zuurbier, Phillis Lakeman, Allan Bayat, Julian Martinez, Rebecca Signer, Pernille M. Torring, Morten Buch Engelund, Karen W. Gripp, Louise Amlie‐Wolf, Lindsay B. Henderson, Alina T. Midro, Eugeniusz Tarasów, Beata Stasiewicz‐Jarocka, Diana Moskal‐Jasinska, Paul Vos, Felix Boschann, Corinna Stoltenburg, Oliver Puk, Inger‐Lise Mero, Kristine Lossius, Cyril Mignot, Boris Keren, Johanna C. Acosta Guio, Ignacio Briceño, Alberto Gomez, Yaping Yang, and Pawel Stankiewicz. Phenotypic expansion of the bptf‐related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies. American Journal of Medical Genetics. Part a, 185:1366-1378, Jan 2021. URL: https://doi.org/10.1002/ajmg.a.62102, doi:10.1002/ajmg.a.62102. This article has 33 citations and is from a peer-reviewed journal.
(glinton2021phenotypicexpansionof pages 4-5): Kevin E. Glinton, Anna C. E. Hurst, Kevin M. Bowling, Ingrid Cristian, Devon Haynes, Dusit Adstamongkonkul, Oskar Schnappauf, David B. Beck, Carole Brewer, Aditi Shah Parikh, Deepali N. Shinde, Alan Donaldson, Ariel Brautbar, Saskia Koene, Arie van Haeringen, Amélie Piton, Yline Capri, Margherita Furlan, Elena Gardella, Rikke Steensbjerre Møller, Irma van de Beek, Linda Zuurbier, Phillis Lakeman, Allan Bayat, Julian Martinez, Rebecca Signer, Pernille M. Torring, Morten Buch Engelund, Karen W. Gripp, Louise Amlie‐Wolf, Lindsay B. Henderson, Alina T. Midro, Eugeniusz Tarasów, Beata Stasiewicz‐Jarocka, Diana Moskal‐Jasinska, Paul Vos, Felix Boschann, Corinna Stoltenburg, Oliver Puk, Inger‐Lise Mero, Kristine Lossius, Cyril Mignot, Boris Keren, Johanna C. Acosta Guio, Ignacio Briceño, Alberto Gomez, Yaping Yang, and Pawel Stankiewicz. Phenotypic expansion of the bptf‐related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies. American Journal of Medical Genetics. Part a, 185:1366-1378, Jan 2021. URL: https://doi.org/10.1002/ajmg.a.62102, doi:10.1002/ajmg.a.62102. This article has 33 citations and is from a peer-reviewed journal.
(glinton2021phenotypicexpansionof pages 9-10): Kevin E. Glinton, Anna C. E. Hurst, Kevin M. Bowling, Ingrid Cristian, Devon Haynes, Dusit Adstamongkonkul, Oskar Schnappauf, David B. Beck, Carole Brewer, Aditi Shah Parikh, Deepali N. Shinde, Alan Donaldson, Ariel Brautbar, Saskia Koene, Arie van Haeringen, Amélie Piton, Yline Capri, Margherita Furlan, Elena Gardella, Rikke Steensbjerre Møller, Irma van de Beek, Linda Zuurbier, Phillis Lakeman, Allan Bayat, Julian Martinez, Rebecca Signer, Pernille M. Torring, Morten Buch Engelund, Karen W. Gripp, Louise Amlie‐Wolf, Lindsay B. Henderson, Alina T. Midro, Eugeniusz Tarasów, Beata Stasiewicz‐Jarocka, Diana Moskal‐Jasinska, Paul Vos, Felix Boschann, Corinna Stoltenburg, Oliver Puk, Inger‐Lise Mero, Kristine Lossius, Cyril Mignot, Boris Keren, Johanna C. Acosta Guio, Ignacio Briceño, Alberto Gomez, Yaping Yang, and Pawel Stankiewicz. Phenotypic expansion of the bptf‐related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies. American Journal of Medical Genetics. Part a, 185:1366-1378, Jan 2021. URL: https://doi.org/10.1002/ajmg.a.62102, doi:10.1002/ajmg.a.62102. This article has 33 citations and is from a peer-reviewed journal.
(glinton2021phenotypicexpansionof pages 13-13): Kevin E. Glinton, Anna C. E. Hurst, Kevin M. Bowling, Ingrid Cristian, Devon Haynes, Dusit Adstamongkonkul, Oskar Schnappauf, David B. Beck, Carole Brewer, Aditi Shah Parikh, Deepali N. Shinde, Alan Donaldson, Ariel Brautbar, Saskia Koene, Arie van Haeringen, Amélie Piton, Yline Capri, Margherita Furlan, Elena Gardella, Rikke Steensbjerre Møller, Irma van de Beek, Linda Zuurbier, Phillis Lakeman, Allan Bayat, Julian Martinez, Rebecca Signer, Pernille M. Torring, Morten Buch Engelund, Karen W. Gripp, Louise Amlie‐Wolf, Lindsay B. Henderson, Alina T. Midro, Eugeniusz Tarasów, Beata Stasiewicz‐Jarocka, Diana Moskal‐Jasinska, Paul Vos, Felix Boschann, Corinna Stoltenburg, Oliver Puk, Inger‐Lise Mero, Kristine Lossius, Cyril Mignot, Boris Keren, Johanna C. Acosta Guio, Ignacio Briceño, Alberto Gomez, Yaping Yang, and Pawel Stankiewicz. Phenotypic expansion of the bptf‐related neurodevelopmental disorder with dysmorphic facies and distal limb anomalies. American Journal of Medical Genetics. Part a, 185:1366-1378, Jan 2021. URL: https://doi.org/10.1002/ajmg.a.62102, doi:10.1002/ajmg.a.62102. This article has 33 citations and is from a peer-reviewed journal.

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Classifications

Inheritance

Discussions and Knowledge Gaps

Pathophysiology

Pathograph

Phenotypes

Genetic Associations

Variants

Medical Actions

Diagnosis

Prevalence

Differential Diagnoses

Related Datasets

Experimental Models

Animal Models

Source YAML

References & Deep Research

References

Deep Research

BPTF-Related Neurodevelopmental Disorder: Comprehensive Disease-Characteristics Report

Executive summary and evidence limits

1. Disease information

Definition and nomenclature

Identifiers

2. Etiology

Causal factor

Genetic risk

Environmental and protective factors

3. Phenotypes

Neurodevelopmental and neurologic features

Growth, craniofacial, skeletal, and ocular features

Behavioral, laboratory, and quality-of-life data

4. Genetic and molecular information

Gene and variant spectrum

Functional consequence and epigenetics

5. Environmental information

6. Mechanism and pathophysiology

Causal chain

Suggested functional ontology

Molecular profiling and advanced technologies

7. Anatomical structures affected

8. Temporal development

9. Inheritance and population

10. Diagnostics

Recommended genomic approach

Clinical evaluation after diagnosis

Differential diagnosis

11. Outcome and prognosis

12. Treatment and real-world implementation

13. Prevention

14. Other species and natural disease

15. Model organisms

Zebrafish

Mouse

Recent research and authoritative interpretation

Key primary sources and abstract quotations

Knowledge-base-ready summary

Critical data gaps

Artifacts

Reference Validation