Alopecia-Intellectual Disability Syndrome 1

Mendelian MONDO:0021035 Pathograph 10 Show in embeddings browser

Alopecia-intellectual disability syndrome 1 (APMR1; OMIM #203650) is a very rare autosomal recessive neuroectodermal syndrome combining total or partial absence of hair from the scalp and other body sites with variable intellectual disability. The APMR1 locus was mapped by genome-wide linkage to chromosome 3q26.33-q27.3 in a large consanguineous Pakistani kindred, and a homozygous AHSG missense variant (NM_001622:c.950G>A, p.Arg317His) segregating in a large consanguineous family with seven affected members subsequently identified AHSG — alpha-2-HS-glycoprotein, the gene encoding the plasma glycoprotein fetuin-A — as the causal gene. AHSG maps to 3q27.3, inside the original linkage interval. The mechanism connecting fetuin-A to hair and brain development is not established. Fetuin-A's best-characterised roles — systemic inhibition of ectopic calcification and antagonism of TGF-beta/BMP family signalling — do not obviously predict this phenotype, and the Ahsg-null mouse is reported as phenotypically normal apart from ectopic calcification on a mineralising diet. This entry therefore models the proximal molecular lesion as established and the route from it to alopecia and intellectual disability as an explicitly hypothetical TGF-beta-antagonism model, flagged with a HUMAN_MODEL_MISMATCH discussion. APMR1 is one of four numbered forms in the alopecia-intellectual disability syndrome (APMR) series (MONDO:0008756). Only two are molecularly characterised — APMR1 (AHSG, 3q27.3) and APMR4 (LSS, 21q22.3, curated at kb/disorders/Alopecia-Intellectual_Disability_Syndrome_4.yaml) — while the APMR2 (3q26.2-q26.31) and APMR3 (18q11.2-q12.2) loci remain uncharacterised. Because the numbered forms are separate diseases with different genes on different chromosomes rather than a single-gene severity spectrum, the series is modelled as a Grouping (kb/groupings/Alopecia-Intellectual_Disability_Syndromes.yaml) over the member Disease entries, NOT as one umbrella Disease with has_subtypes.

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1
Inheritance
5
Pathophys.
6
Phenotypes
1
Hypotheses
3
Gaps
10
Pathograph
1
Genes
1
Variants
2
Medical Actions
3
Differentials
1
Models
3
References
1
Deep Research
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Inheritance

1
Autosomal Recessive HP:0000007
APMR1 segregates as an autosomal recessive trait in large consanguineous kindreds. Affected individuals in the AHSG-solved family are homozygous for p.Arg317His and the variant falls within runs of homozygosity; heterozygous carriers are unaffected.
Autosomal recessive inheritance
Show evidence (2 references)
PMID:28054173 SUPPORT Human Clinical
"Alopecia with mental retardation syndrome (APMR) is a very rare autosomal recessive condition that is associated with total or partial absence of hair from the scalp and other parts of the body as well as variable intellectual disability."
States both the recessive inheritance pattern and the cardinal two-component phenotype.
PMID:28054173 SUPPORT Human Clinical
"Here we present whole-exome sequencing results of a large consanguineous family segregating APMR syndrome with seven affected family members."
Segregation across seven affected members of one consanguineous kindred is the basis for the recessive model.
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Mechanistic Hypotheses

1
Loss of fetuin-A TGF-beta antagonism model
fetuin_tgfb_antagonism_model EMERGING
Evidence balance 2 support
A candidate explanatory model in which the APMR1 phenotype follows from loss of fetuin-A's function as an antagonist of TGF-beta family signalling. Fetuin-A is a potent TGF-beta antagonist, and TGF-beta2 is the isoform that induces catagen (the regression phase) of the human hair cycle: in human hair follicle organ culture, adding fetuin markedly elongates follicles in a concentration-dependent manner. Reduced fetuin-A antagonism would therefore be expected to leave TGF-beta2 signalling unopposed in the follicle. AHSG is separately reported to be expressed in the fetal human brain and believed to be involved in embryonic neocortical development, offering a parallel route to the neurodevelopmental arm. This model is EMERGING, not canonical. Every step downstream of the AHSG variant is inferred from fetuin-A biology studied outside APMR1 — none of it has been shown in APMR1 patient tissue, and no functional rescue experiment has been reported for p.Arg317His. A concrete competing route exists and is not modelled here. Sailani et al., who identified the gene, proposed a more disease-specific mechanism: AHSG is expressed in developing hair follicles at the stage where basal keratinocytes reorganise into follicular placodes, is expressed more in fetal than postnatal skin, and promotes primary keratinocyte migration; a parallel argument places it in early neocortical neurons. That is a placode-formation and cell-migration model rather than a TGF-beta-antagonism one, and it may well be the better explanation. It is not curated as pathophysiology nodes because those observations sit in the paywalled full text of PMID:28054173, whose cache entry is abstract-only, so no verified snippet can support them, not because the evidence for them is weaker. See section 6 of research/Alopecia-Intellectual_Disability_Syndrome_1-deep-research-falcon.md. Two further possibilities are also unexcluded: that the phenotype arises from a fetuin-A function unrelated to any of these, or from a second variant in linkage disequilibrium within the run of homozygosity.
Pathograph links
Aberrant Fetuin-A Protein Processing -> Reduced Fetuin-A TGF-beta Antagonism INDIRECT UNKNOWN INTERMEDIATES A processing-defective fetuin-A is postulated to provide less TGF-beta antagonism. This step is inferred, not measured, in APMR1.
Reduced Fetuin-A TGF-beta Antagonism -> Premature Hair Follicle Catagen Entry INDIRECT UNKNOWN INTERMEDIATES Unopposed TGF-beta2 signalling in the follicle is proposed to drive premature or persistent catagen entry.
Reduced Fetuin-A TGF-beta Antagonism -> Impaired Neocortical Development INDIRECT UNKNOWN INTERMEDIATES A parallel route to the neurodevelopmental arm, resting on AHSG expression in the fetal human brain rather than on any measurement in APMR1.
Premature Hair Follicle Catagen Entry -> Alopecia of Scalp INDIRECT UNKNOWN INTERMEDIATES Failure to sustain anagen manifests clinically as absent or sparse scalp hair.
Impaired Neocortical Development -> Intellectual Disability INDIRECT UNKNOWN INTERMEDIATES Disturbed neocortical development is proposed to underlie the variable intellectual disability.
Show evidence (2 references)
PMID:12060393 SUPPORT In Vitro
"In the presence of the antibody as well as fetuin, hair follicles were markedly elongated in a concentration-dependent manner."
Fetuin promotes human hair follicle elongation in organ culture, which is the observation the loss-of-antagonism model is built on.
PMID:12853704 SUPPORT Other
"This glycoprotein is expressed in the fetal human brain and is believed to be involved in the embryonic development of the neocortex."
Supports a plausible neurodevelopmental role for AHSG, but is a background statement in a glioma proteomics paper rather than a primary developmental result, so it is graded PARTIAL.
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Discussions and Knowledge Gaps

3
Is AHSG established as the APMR1 gene, given that the assignment rests on one consanguineous family, one predicted-pathogenic missense allele, and no functional rescue?
KNOWLEDGE GAP OPEN apmr1_ahsg_gene_validity
Attached to
pathophysiology#Biallelic AHSG Missense Variant genetic#AHSG
The AHSG assignment has real positional support: the gene lies inside the independently mapped 3q26.33-q27.3 interval and within a run of homozygosity, and the mutant protein migrates aberrantly. But it is a single-family, single-allele report from 2017 and, as of this curation, no second family with an independent AHSG allele has been published, no functional assay establishes the direction of effect, and ClinGen has curated no gene-disease validity assertion for AHSG. The Ahsg-null mouse being phenotypically normal cuts against a simple loss-of-function model. The entry therefore records mechanism_confidence PROVISIONAL on the trigger node and PROVISIONAL on the trigger node and LIKELY_PATHOGENIC rather than PATHOGENIC on the variant. A further complication, surfaced by the Edison deep-research run: a different homozygous AHSG allele — the nonsense p.Lys2Ter, with complete serum fetuin-A deficiency confirmed by ELISA — has been reported to cause infantile cortical hyperostosis rather than APMR1. Two AHSG genotypes, two unrelated phenotypes, one family each. This is either an allelic series in which the missense acts by a non-null mechanism, or a sign that one of the two assignments is wrong. Resolving it needs a second unrelated APMR1 family or a functional readout, not more reviews restating the 2017 result.
Show evidence (2 references)
PMID:28054173 SUPPORT Human Clinical
"Previous families with APMR syndrome have been studied through linkage analyses and the linkage resolution did not allow pointing out to a single gene candidate."
The authors note that prior linkage work could not resolve a single candidate, underlining that this is the first and so far only gene-level report.
PMID:31288248 SUPPORT Human Clinical
"A novel homozygous nonsense mutation in AHSG gene has been found in ICH patient with a typical phenotype, resulting in fetuin-A deficiency."
A second, independent biallelic AHSG genotype associated with an entirely different phenotype, which complicates the APMR1 gene-disease assertion.
Why is the Ahsg-null mouse phenotypically normal when biallelic human AHSG variants cause alopecia and intellectual disability?
HUMAN MODEL MISMATCH OPEN apmr1_ahsg_mouse_mismatch
Attached to
pathophysiology#Reduced Fetuin-A TGF-beta Antagonism animal_models#Mouse
Model-system evidence for AHSG exists and is substantial, but it is about the wrong thing: the Ahsg-null mouse was built and characterised as a calcification model and is otherwise reported as phenotypically normal, with no hair or neurodevelopmental phenotype. This is a genuine mismatch rather than merely missing evidence, and it admits at least three readings that current data cannot separate. First, the human allele is a missense, not a null, so APMR1 may act by a dominant-negative or neomorphic mechanism that a knockout cannot model. Second, mouse and human may differ in how far hair-follicle cycling and cortical development depend on fetuin-A — notably, the human catagen evidence underpinning this model comes from human follicle organ culture, not mouse. Third, the mouse may simply never have been examined for the relevant phenotypes, since the study's endpoints were mineral. The human allelic series makes the first reading the most likely one. A homozygous AHSG nonsense allele with ELISA-confirmed complete fetuin-A deficiency causes infantile cortical hyperostosis, not APMR1 — so in humans, as in mice, absence of fetuin-A does not produce alopecia with intellectual disability. That converts the mouse result from an awkward species difference into a consistent cross-species signal that APMR1 is not a simple null phenotype. Until an allele-specific model exists, every node downstream of the variant stays HYPOTHETICAL.
Proposed experiments
Targeted dermatological and neurobehavioural phenotyping of Ahsg-/- mice
apmr1_ahsg_ko_targeted_phenotyping
Phenotype an existing Ahsg-null line specifically for hair-cycle staging (anagen/ catagen distribution on synchronised depilation), follicle histology, and standard neurobehavioural and cortical-layering assays, rather than relying on the absence of a reported phenotype in a calcification study.
Would support
pathophysiology#Premature Hair Follicle Catagen Entry
Would refute
pathophysiology#Reduced Fetuin-A TGF-beta Antagonism
Supporting outcome
  • Ahsg-/- mice show accelerated catagen entry after depilation-synchronised anagen, reduced follicle length, or cortical layering abnormalities.
Refuting outcome
  • Systematic hair-cycle staging and neurobehavioural testing find no difference from wild-type, indicating that simple loss of fetuin-A is insufficient and directing attention to an allele-specific mechanism.
Knock-in mouse carrying the orthologous p.Arg317His allele
apmr1_ahsg_r317h_knockin
Generate a knock-in of the orthologous Ahsg missense substitution rather than a null, to test whether the human phenotype depends on the specific allele rather than on absence of the protein.
Would support
pathophysiology#Biallelic AHSG Missense Variant
Would refute
pathophysiology#Biallelic AHSG Missense Variant
Supporting outcome
  • Homozygous knock-in mice develop hair loss and/or cognitive impairment that the null does not, supporting an allele-specific (dominant-negative or neomorphic) mechanism.
Refuting outcome
  • Homozygous knock-in mice are indistinguishable from both wild-type and Ahsg-null mice, which would weaken the case for AHSG as the causal gene and revive the possibility of another variant within the run of homozygosity.
Show evidence (2 references)
PMID:12897203 REFUTE Model Organism
"Ahsg-deficient mice are phenotypically normal, but develop severe calcification of various organs on a mineral and vitamin D-rich diet and on a normal diet when the deficiency is combined with a DBA/2 genetic background."
The negative mouse result that creates the mismatch.
PMID:31288248 REFUTE Human Clinical
"By enzyme-linked immunosorbent assay (ELISA), we show a complete deficiency of this protein in the patient's serum, compared to controls."
A human with no fetuin-A at all has a skeletal phenotype, not APMR1, which refutes the simple loss-of-function reading in the species that matters.
Which gene belongs to which numbered APMR form, and how should the series be modelled in dismech?
INTERPRETATION RESOLVED apmr1_locus_series_confusion
Attached to
disease#Alopecia-Intellectual Disability Syndrome 1
Secondary sources describing this numbered series have attributed LSS to APMR1 and to APMR3, and have introduced an "HR locus" that belongs to a different disease entirely. Tracing the primary papers separates them cleanly: APMR1 maps to 3q26.33-q27.3 with AHSG at 3q27.3; APMR2 maps to a distinct, non-overlapping 3q26.2-q26.31 interval; APMR3 maps to chromosome 18q11.2-q12.2, nowhere near LSS; and LSS is at 21q22.3 and belongs to APMR4 only. Because the four forms have different genes on different chromosomes, they are separate diseases and the series is modelled as a Grouping over member Disease entries rather than as one Disease with has_subtypes.
Resolution: Resolved for this entry by curating APMR1 as its own Disease bound to MONDO:0021035 and creating kb/groupings/Alopecia-Intellectual_Disability_Syndromes.yaml as the union over APMR1 and APMR4. APMR2 and APMR3 stay uncurated because they have no gene.
Show evidence (2 references)
PMID:16922726 SUPPORT Human Clinical
"The linkage interval of the APMR locus identified here does not overlap with the one described previously; therefore, this locus has been designated as APMR2."
Establishes APMR2 as a locus distinct from and non-overlapping with APMR1.
PMID:33881165 SUPPORT Human Clinical
"while the remaining two uncharacterized loci, that is, APMR2 and APMR3, are reported in the Pakistani population"
Confirms APMR2 and APMR3 have no assigned gene, so neither can be curated as a Disease.
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Pathophysiology

5
Biallelic AHSG Missense Variant
A homozygous missense variant in AHSG (NM_001622:exon7:c.950G>A, p.Arg317His) was identified by whole-exome sequencing as the candidate cause of APMR1. The residue lies in a region of the protein required for protein processing and the substitution disrupts a phosphorylation motif. AHSG maps within the previously reported APMR1 linkage interval and the variant falls within a run of homozygosity. Confidence is PROVISIONAL rather than ESTABLISHED: the assertion rests on a single consanguineous family, a single predicted-pathogenic missense allele, and no reported functional rescue. No independent family with a second AHSG allele has been published, and ClinGen has not curated an AHSG gene-disease validity assertion.
AHSG hgnc:349 HUGO Gene Nomenclature Committee (hgnc) Relation: this pathophysiological event involves this gene This pathophysiological event involves AHSG (hgnc:349). hgnc:349 is a gene from the HUGO Gene Nomenclature Committee.
Downstream
Aberrant Fetuin-A Protein Processing The substituted residue lies in a region required for protein processing and disrupts a phosphorylation motif, and the mutant protein migrates aberrantly.
Show evidence (3 references)
PMID:28054173 SUPPORT Human Clinical
"Our study revealed a novel predicted pathogenic, homozygous missense mutation in the AHSG (OMIM 138680) gene (AHSG: NM_001622:exon7:c.950G>A:p.Arg317His)."
Identifies the specific causal allele and its zygosity.
PMID:28054173 SUPPORT Human Clinical
"Consistent with the phenotype, AHSG maps within APMR linkage region 1 (APMR 1) as reported before, and falls within runs of homozygosity (ROH)."
Positional concordance with the independently mapped APMR1 locus supports the gene assignment.
PMID:16273389 SUPPORT Human Clinical
"Recombination events observed in affected individuals localized the disease locus between markers D3S1232 and D3S2436, spanning 11.49-cM region on chromosome 3q26.33-q27.3."
The original linkage interval that AHSG was later found to lie within.
Aberrant Fetuin-A Protein Processing
The p.Arg317His protein migrates with an aberrant size relative to that of healthy individuals, the only direct experimental evidence that the variant alters the protein product. Whether this reflects altered post-translational modification, reduced secretion, or reduced functional activity was not determined, and no quantitative assay of circulating fetuin-A in affected individuals has been reported.
Loss of fetuin-A TGF-beta antagonism model
AHSG hgnc:349 HUGO Gene Nomenclature Committee (hgnc) Relation: this pathophysiological event involves this gene This pathophysiological event involves AHSG (hgnc:349). hgnc:349 is a gene from the HUGO Gene Nomenclature Committee.
Downstream
Reduced Fetuin-A TGF-beta Antagonism A processing-defective fetuin-A is postulated to provide less TGF-beta antagonism. This step is inferred, not measured, in APMR1. Loss of fetuin-A TGF-beta antagonism model
Show evidence (1 reference)
PMID:28054173 SUPPORT Human Clinical
"In addition, the altered protein migrates with an aberrant size relative to healthy individuals."
Direct observation that the variant changes the fetuin-A protein product.
Reduced Fetuin-A TGF-beta Antagonism
Fetuin-A is a potent antagonist of TGF-beta family signalling. The model proposes that a processing-defective fetuin-A antagonises TGF-beta less effectively, leaving TGF-beta signalling relatively unopposed in tissues that depend on fetuin-A for this restraint. No measurement of TGF-beta pathway activity has been reported in APMR1 patient tissue, so this node is HYPOTHETICAL.
Loss of fetuin-A TGF-beta antagonism model
negative regulation of transforming growth factor beta receptor signaling pathway GO:0030512 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves decreased negative regulation of transforming growth factor beta receptor signaling pathway (GO:0030512). GO:0030512 is a biological process from the Gene Ontology. ↓ DECREASED
Downstream
Premature Hair Follicle Catagen Entry Unopposed TGF-beta2 signalling in the follicle is proposed to drive premature or persistent catagen entry. Loss of fetuin-A TGF-beta antagonism model
Impaired Neocortical Development A parallel route to the neurodevelopmental arm, resting on AHSG expression in the fetal human brain rather than on any measurement in APMR1. Loss of fetuin-A TGF-beta antagonism model
Show evidence (3 references)
PMID:8662721 SUPPORT In Vitro
"Surface plasmon resonance measurements show that fetuin binds directly to TGF-beta1 and TGF-beta2 and with greater affinity to the TGF-beta-related bone morphogenetic proteins (BMP-2, BMP-4, and BMP-6)."
Direct binding measurements establishing the ligand-sequestration mechanism of fetuin-A that this node describes losing.
PMID:8662721 SUPPORT In Vitro
"suggest that fetuin is a natural antagonist of TGF-beta and BMP activities"
The authors' summary of fetuin as a physiological TGF-beta/BMP antagonist.
PMID:12060393 SUPPORT In Vitro
"Next, a neutralizing antibody and fetuin, a potent transforming growth factor-beta antagonist was tested."
Independent confirmation of the antagonist function, in the hair-follicle context.
Premature Hair Follicle Catagen Entry
TGF-beta2 induces catagen, the regression phase of the human hair cycle: it is strongly immunoreactive in lower bulb matrix cells at the anagen-catagen transition and colocalises with its type II receptor in regressing epithelial strands containing apoptotic cells. Exogenous TGF-beta2 suppresses hair elongation in organ culture, while fetuin markedly elongates follicles. The model proposes that failure of fetuin-A antagonism shifts follicles toward catagen, but this has not been shown in APMR1 skin, and no scalp biopsy or follicle histology has been reported for an AHSG-variant patient.
Loss of fetuin-A TGF-beta antagonism model
hair follicle cell CL:0002559 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves hair follicle cell (CL:0002559). CL:0002559 is a cell type from the Cell Ontology.
hair follicle development GO:0001942 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves decreased hair follicle development (GO:0001942). GO:0001942 is a biological process from the Gene Ontology. ↓ DECREASED
Animal models
Ahsg-null mouse Mouse fails to recapitulate Complete loss of Ahsg in the mouse does not produce the hair phenotype that a human biallelic AHSG variant produces, which is the central difficulty for any loss-of-function model of APMR1.
Downstream
Alopecia of Scalp Failure to sustain anagen manifests clinically as absent or sparse scalp hair. Loss of fetuin-A TGF-beta antagonism model
Show evidence (2 references)
PMID:12060393 SUPPORT In Vitro
"Elongation of hair was significantly suppressed by transforming growth factor-beta2."
Direct demonstration that TGF-beta2 suppresses human hair growth in organ culture.
PMID:12060393 SUPPORT In Vitro
"During the anagen-catagen transition phase, strong transforming growth factor-beta2 immunoreactivity appeared in the lower bulb matrix cells adjacent to the dermal papilla."
Localises the catagen-inducing TGF-beta2 signal to the follicle compartment.
Impaired Neocortical Development
AHSG is reported to be expressed in the fetal human brain and believed to be involved in embryonic neocortical development. The model proposes that a processing-defective fetuin-A perturbs this role, producing the intellectual disability component. No neuroimaging series, neuropathology, or patient-derived neural model has been reported for AHSG-variant individuals, so the node rests entirely on background expression data from an unrelated study population.
Loss of fetuin-A TGF-beta antagonism model
cerebral cortex development GO:0021987 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves abnormal cerebral cortex development (GO:0021987). GO:0021987 is a biological process from the Gene Ontology. ⚠ ABNORMAL
Downstream
Intellectual Disability Disturbed neocortical development is proposed to underlie the variable intellectual disability. Loss of fetuin-A TGF-beta antagonism model
Show evidence (1 reference)
PMID:12853704 SUPPORT Other
"This glycoprotein is expressed in the fetal human brain and is believed to be involved in the embryonic development of the neocortex."
The sole published basis for a neocortical role of AHSG; a background statement, not a primary developmental finding, so graded PARTIAL.
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Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence and cross-linked metadata.
Pathograph: causal mechanism network for Alopecia-Intellectual Disability Syndrome 1 Interactive directed graph showing how pathophysiology mechanisms, phenotypes, genetic factors and variants, experimental models, environmental triggers, and treatments relate through causal and linked edges.
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Phenotypes

6
Integument 1
Absent Axillary Hair HP:0002221 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Absent axillary hair (HP:0002221). HP:0002221 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:17451405 SUPPORT Human Clinical
"Affected individuals with APMR syndrome show loss of hair on the scalp, absence of eyebrows, eyelashes, axillary and pubic hair, and mild to severe mental retardation."
States absence of axillary hair as a feature of the APMR phenotype.
Nervous System 1
Intellectual Disability OBLIGATE HP:0001249 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Intellectual disability (HP:0001249). HP:0001249 is a phenotype from the Human Phenotype Ontology.
Show evidence (3 references)
PMID:28054173 SUPPORT Human Clinical
"as well as variable intellectual disability"
Documents the neurodevelopmental component and its variability.
PMID:33881165 SUPPORT Human Clinical
"mild to severe intellectual disability"
Gives the reported severity range across the APMR series.
PMID:17451405 SUPPORT Human Clinical
"Affected individuals with APMR syndrome show loss of hair on the scalp, absence of eyebrows, eyelashes, axillary and pubic hair, and mild to severe mental retardation."
Gives the full hair distribution (including axillary and pubic hair) alongside the mild-to-severe cognitive range for the APMR series.
Other 4
Alopecia of Scalp OBLIGATE HP:0002293 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Alopecia of scalp (HP:0002293). HP:0002293 is a phenotype from the Human Phenotype Ontology.
Show evidence (2 references)
PMID:28054173 SUPPORT Human Clinical
"associated with total or partial absence of hair from the scalp and other parts of the body"
Documents the extent and distribution of the hair loss.
PMID:33881165 SUPPORT Human Clinical
"absence of hair on the scalp, eyelashes, and eyebrows and mild to severe intellectual disability"
Confirms scalp involvement across the APMR series.
Absent Eyebrow HP:0002223 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Absent eyebrow (HP:0002223). HP:0002223 is a phenotype from the Human Phenotype Ontology.
Show evidence (2 references)
PMID:17451405 SUPPORT Human Clinical
"Affected individuals with APMR syndrome show loss of hair on the scalp, absence of eyebrows, eyelashes, axillary and pubic hair, and mild to severe mental retardation."
States absence of eyebrows as a feature of the APMR phenotype.
PMID:33881165 SUPPORT Human Clinical
"absence of hair on the scalp, eyelashes, and eyebrows and mild to severe intellectual disability"
Independent review confirming eyebrow involvement.
Absent Eyelashes HP:0000561 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Absent eyelashes (HP:0000561). HP:0000561 is a phenotype from the Human Phenotype Ontology.
Show evidence (2 references)
PMID:17451405 SUPPORT Human Clinical
"Affected individuals with APMR syndrome show loss of hair on the scalp, absence of eyebrows, eyelashes, axillary and pubic hair, and mild to severe mental retardation."
States absence of eyelashes as a feature of the APMR phenotype.
PMID:33881165 SUPPORT Human Clinical
"absence of hair on the scalp, eyelashes, and eyebrows and mild to severe intellectual disability"
Independent review confirming eyelash involvement.
Absent Pubic Hair HP:0002555 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Absent pubic hair (HP:0002555). HP:0002555 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:17451405 SUPPORT Human Clinical
"Affected individuals with APMR syndrome show loss of hair on the scalp, absence of eyebrows, eyelashes, axillary and pubic hair, and mild to severe mental retardation."
States absence of pubic hair as a feature of the APMR phenotype.
🧬

Genetic Associations

1
AHSG
Gene: AHSG hgnc:349 HUGO Gene Nomenclature Committee (hgnc) Relation: this disease-associated gene is this gene This disease-associated gene is AHSG (hgnc:349). hgnc:349 is a gene from the HUGO Gene Nomenclature Committee. relationship_type: CAUSATIVE variant_origin: GERMLINE
Show evidence (2 references)
PMID:33881165 SUPPORT Human Clinical
"Among them, AHSG was reported in a consanguineous Iranian family and LSS gene in a Swiss origin family, while the remaining two uncharacterized loci, that is, APMR2 and APMR3, are reported in the Pakistani population."
Independent review confirming AHSG as the APMR1 gene and, importantly, that only APMR1 and APMR4 are molecularly characterised.
PMID:28054173 SUPPORT Human Clinical
"Our study is the first report to identify a homozygous missense mutation for APMR syndrome through whole-exome sequencing."
The authors' own framing as a first report is the reason this gene-disease assertion is curated as PROVISIONAL rather than ESTABLISHED.
Variants (1)
NM_001622:c.950G>A (p.Arg317His) Likely Pathogenic
Gene: AHSG hgnc:349 HUGO Gene Nomenclature Committee (hgnc) Relation: this variant is in this gene This variant is in AHSG (hgnc:349). hgnc:349 is a gene from the HUGO Gene Nomenclature Committee. missense
Germline homozygous missense substitution in AHSG exon 7, reported as predicted pathogenic, affecting a region required for protein processing and disrupting a phosphorylation motif. Curated as LIKELY_PATHOGENIC rather than PATHOGENIC: the supporting data are segregation in one consanguineous family plus in silico prediction, with the only experimental readout an altered protein migration on Western blot. No functional assay establishes the direction of effect, so whether the allele is loss-of-function, dominant-negative, or neomorphic is unresolved. A simple loss-of-function reading is actively disfavoured by the human allelic series: a homozygous AHSG nonsense allele (p.Lys2Ter) causing complete fetuin-A deficiency on ELISA has been reported to cause infantile cortical hyperostosis (Caffey disease), not alopecia with intellectual disability. If total absence of fetuin-A gives a skeletal phenotype, p.Arg317His is unlikely to act by simple absence of protein. Note that the schema's ClinicalSignificanceEnum offers no uncertain-significance (VUS) tier, so LIKELY_PATHOGENIC is the closest available grade rather than an exact reflection of the ACMG evidence here.
Identifiers: dbSNP:rs201849460
Show evidence (1 reference)
PMID:28054173 SUPPORT Human Clinical
"Our study revealed a novel predicted pathogenic, homozygous missense mutation in the AHSG (OMIM 138680) gene (AHSG: NM_001622:exon7:c.950G>A:p.Arg317His)."
The primary report of the allele, its zygosity, and its predicted pathogenicity.
💊

Medical Actions

2
Supportive and Developmental Care
Action: Supportive CareNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is Supportive Care (NCIT:C15747). NCIT:C15747 is a clinical intervention from the NCI Thesaurus. NCIT:C15747
There is no disease-modifying therapy for APMR1 and no interventional trial has ever been registered. Management is supportive and multidisciplinary: early developmental intervention and special education for the intellectual disability, with speech, occupational and physical therapy as needed, plus dermatological care of the hairless scalp (sun protection, scalp care, and hair prostheses where wanted).
Genetic Counseling
Action: Genetic CounselingNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is Genetic Counseling (NCIT:C15240). NCIT:C15240 is a clinical intervention from the NCI Thesaurus. NCIT:C15240
Genetic counselling is the one intervention with a concrete, actionable basis in APMR1. The disorder is autosomal recessive and every reported family is consanguineous, so recurrence risk and cascade carrier testing are the practical questions families face. Testing is possible because the causal allele is known in the one solved family.
Show evidence (1 reference)
PMID:28054173 SUPPORT Human Clinical
"Here we present whole-exome sequencing results of a large consanguineous family segregating APMR syndrome with seven affected family members."
Consanguinity and recessive segregation in a large kindred are what make recurrence counselling and cascade testing the relevant intervention.
🔬

Diagnosis

1
Molecular genetic testing
APMR1 is confirmed by identifying biallelic pathogenic AHSG variants. The gene was itself discovered by whole-exome sequencing, and in practice a clinical diagnosis of congenital alopecia with intellectual disability is resolved to a numbered APMR form only by sequencing, since the four forms are clinically overlapping and are separated by gene rather than by phenotype.
molecular genetic testing NCIT:C15709 NCI Thesaurus (NCIT)
Results: Biallelic pathogenic AHSG variants confirming APMR1.
Serum fetuin-A electrophoresis is deliberately NOT curated as a diagnostic test. The aberrant migration of the mutant protein is a single research observation in one family, with no reported sensitivity, specificity, reference interval, or independent replication, and the deep-research run classified it as research-level rather than a validated clinical assay. Promoting it to `diagnosis:` would overstate it.
Show evidence (2 references)
PMID:28054173 SUPPORT Human Clinical
"Our study is the first report to identify a homozygous missense mutation for APMR syndrome through whole-exome sequencing."
Establishes exome sequencing as the route by which an APMR1 diagnosis is made.
PMID:28054173 SUPPORT Human Clinical
"Previous families with APMR syndrome have been studied through linkage analyses and the linkage resolution did not allow pointing out to a single gene candidate."
Explains why sequencing rather than linkage is the diagnostic route: linkage localises but does not identify the gene.
📊

Prevalence

1
Worldwide
Point Prevalence 0.1 per 100,000 <1 in 1,000,000
The estimate is for the APMR group as a whole, not for APMR1 specifically. APMR1 itself is documented in a small number of consanguineous kindreds (predominantly Pakistani and Iranian) rather than by any formal epidemiological study.
Show evidence (2 references)
PMID:33881165 SUPPORT Human Clinical
"Its precise prevalence is still unknown, but according to a predictive estimate, it prevails with the ratio of 1 in 1,000,000 persons worldwide."
Predictive prevalence estimate for the APMR group, supporting the BELOW_1_IN_1000000 class.
PMID:33881165 SUPPORT Human Clinical
"So far, approximately 14 families (i.e., Iranian, Pakistani, and Swiss) with APMR have been reported in the scientific literature."
Quantifies the total reported APMR literature, supporting the ultra-rare classification.
🔀

Differential Diagnoses

3

Conditions with similar clinical presentations that must be differentiated from Alopecia-Intellectual Disability Syndrome 1:

Alopecia-Intellectual Disability Syndrome 4 MONDO:0030009
Overlapping Features APMR4, caused by biallelic LSS variants at 21q22.3, presents with the same core combination of congenital alopecia and intellectual disability and is the main within-series differential. It is distinguished by frequent early-onset epilepsy and additional dermatological features, and is separated definitively by gene testing.
Show evidence (1 reference)
PMID:33881165 SUPPORT Human Clinical
"Among them, AHSG was reported in a consanguineous Iranian family and LSS gene in a Swiss origin family"
Establishes APMR1 and APMR4 as distinct gene-defined entities within the series.
Infantile Cortical Hyperostosis (Caffey Disease) Not Yet Curated MONDO:0007244
Overlapping Features Not a clinical mimic but the key allelic comparator. A homozygous AHSG nonsense variant (c.A4T, p.Lys2Ter) producing complete serum fetuin-A deficiency has been reported in an infant with classical infantile cortical hyperostosis — subperiosteal bone hyperplasia, with no alopecia or intellectual disability described. The autosomal dominant form of Caffey disease is caused by COL1A1. Because a human AHSG null gives a skeletal rather than a neurocutaneous phenotype, the APMR1 missense allele is unlikely to act by simple loss of protein; this is the strongest available constraint on the APMR1 mechanism and is stronger than the mouse knockout evidence because it is human. Note the term binding: MONDO:0007244 is the clinical Caffey disease concept, which is predominantly the autosomal dominant COL1A1 entity. MONDO has no class for the AHSG-related recessive form, so the binding here is to the clinical entity rather than to the specific allelic condition described.
Show evidence (2 references)
PMID:31288248 SUPPORT Human Clinical
"WES analysis revealed a novel homozygous nonsense mutation in lysine 2 of fetuin-A, encoded by the ALPHA-2-HS-GLYCOPROTEIN (AHSG) gene (c.A4T; p.K2X)."
Identifies the human AHSG null allele and the disease it causes.
PMID:31288248 SUPPORT Human Clinical
"By enzyme-linked immunosorbent assay (ELISA), we show a complete deficiency of this protein in the patient's serum, compared to controls."
Confirms the allele produces complete fetuin-A deficiency, which is what makes the phenotypic contrast with APMR1 informative.
Atrichia with Papular Lesions Not Yet Curated MONDO:0008847
Overlapping Features HR-related atrichia with papular lesions also presents with near-total congenital hair loss but is caused by variants in HR at 8p21.3, is not accompanied by intellectual disability as a defining feature, and shows characteristic follicular papules. It is named here explicitly because the HR gene has been erroneously attributed to APMR1 in secondary sources.
Show evidence (1 reference)
PMID:33881165 SUPPORT Human Clinical
"The current mini-report discusses the molecular genetics and mutational spectrum of APMR syndrome, its differential diagnosis from related disorders"
The cited review is the source that works through the APMR differential; the specific HR distinction is recorded in the description rather than quoted.
🐁

Animal Models

1
Ahsg-null mouse
The constitutive Ahsg knockout mouse was generated and characterised as a model of ectopic calcification, not of APMR1. It is reported as phenotypically normal at baseline, developing severe organ calcification only on a mineral- and vitamin D-rich diet or on a DBA/2 background. No alopecia or neurodevelopmental phenotype is reported.
Species
Mouse
Genotype
Ahsg-/- (targeted null)
Background
C57BL/6 and DBA/2
Genes
AHSG hgnc:349 HUGO Gene Nomenclature Committee (hgnc) Relation: this experimental model concerns this gene This experimental model concerns AHSG (hgnc:349). hgnc:349 is a gene from the HUGO Gene Nomenclature Committee.
Publication
PMID:12897203
Pathograph links
Premature Hair Follicle Catagen Entry fails to recapitulate fidelity: low Complete loss of Ahsg in the mouse does not produce the hair phenotype that a human biallelic AHSG variant produces, which is the central difficulty for any loss-of-function model of APMR1.
Limitations: The report is a calcification study and did not set out to phenotype hair or behaviour, so "phenotypically normal" is a general statement rather than the result of a targeted dermatological or neurodevelopmental assessment; absence of a reported hair phenotype is therefore weaker than a documented negative. Two further caveats apply: the human allele is a missense substitution rather than a null, so a mouse null is not the matched genotype and a dominant-negative or neomorphic mechanism would not be modelled by it; and mouse and human hair-cycle biology differ, with the human catagen data underpinning this node coming from human follicle organ culture rather than mouse.
Show evidence (1 reference)
PMID:12897203 REFUTE Model Organism
"Ahsg-deficient mice are phenotypically normal, but develop severe calcification of various organs on a mineral and vitamin D-rich diet and on a normal diet when the deficiency is combined with a DBA/2 genetic background."
A constitutive Ahsg null is reported as otherwise phenotypically normal, so the mouse does not reproduce the human hair phenotype.
Listed because its negative result constrains the mechanism model, not because it is a validated APMR1 model. No mouse carrying the orthologous p.Arg317His substitution has been reported.
Show evidence (1 reference)
PMID:12897203 SUPPORT Model Organism
"Taken together, our data demonstrate a critical role of Ahsg as an inhibitor of unwanted mineralization"
Establishes what the Ahsg-null mouse does model — systemic calcification control — which is not the APMR1 phenotype.
{ }

Source YAML

click to show 
name: Alopecia-Intellectual Disability Syndrome 1
synonyms:
- APMR1
- Alopecia with mental retardation syndrome 1
- AHSG-related alopecia-intellectual disability syndrome
- Alopecia-intellectual disability syndrome type 1
creation_date: '2026-08-26T09:00:00Z'
category: Mendelian
description: >
  Alopecia-intellectual disability syndrome 1 (APMR1; OMIM #203650) is a very rare
  autosomal recessive neuroectodermal syndrome combining total or partial absence of
  hair from the scalp and other body sites with variable intellectual disability. The
  APMR1 locus was mapped by genome-wide linkage to chromosome 3q26.33-q27.3 in a
  large consanguineous Pakistani kindred, and a homozygous AHSG missense variant
  (NM_001622:c.950G>A, p.Arg317His) segregating in a large consanguineous family with
  seven affected members subsequently identified AHSG — alpha-2-HS-glycoprotein, the
  gene encoding the plasma glycoprotein fetuin-A — as the causal gene. AHSG maps to
  3q27.3, inside the original linkage interval.

  The mechanism connecting fetuin-A to hair and brain development is not established.
  Fetuin-A's best-characterised roles — systemic inhibition of ectopic calcification
  and antagonism of TGF-beta/BMP family signalling — do not obviously predict this
  phenotype, and the Ahsg-null mouse is reported as phenotypically normal apart from
  ectopic calcification on a mineralising diet. This entry therefore models the
  proximal molecular lesion as established and the route from it to alopecia and
  intellectual disability as an explicitly hypothetical TGF-beta-antagonism model,
  flagged with a HUMAN_MODEL_MISMATCH discussion.

  APMR1 is one of four numbered forms in the alopecia-intellectual disability syndrome
  (APMR) series (MONDO:0008756). Only two are molecularly characterised — APMR1 (AHSG,
  3q27.3) and APMR4 (LSS, 21q22.3, curated at
  kb/disorders/Alopecia-Intellectual_Disability_Syndrome_4.yaml) — while the APMR2
  (3q26.2-q26.31) and APMR3 (18q11.2-q12.2) loci remain uncharacterised. Because the
  numbered forms are separate diseases with different genes on different chromosomes
  rather than a single-gene severity spectrum, the series is modelled as a Grouping
  (kb/groupings/Alopecia-Intellectual_Disability_Syndromes.yaml) over the member
  Disease entries, NOT as one umbrella Disease with has_subtypes.
disease_term:
  preferred_term: alopecia-intellectual disability syndrome 1
  term:
    id: MONDO:0021035
    label: alopecia-intellectual disability syndrome 1
inheritance:
- name: Autosomal Recessive
  inheritance_term:
    preferred_term: Autosomal recessive inheritance
    term:
      id: HP:0000007
      label: Autosomal recessive inheritance
  description: >
    APMR1 segregates as an autosomal recessive trait in large consanguineous kindreds.
    Affected individuals in the AHSG-solved family are homozygous for p.Arg317His and
    the variant falls within runs of homozygosity; heterozygous carriers are
    unaffected.
  evidence:
  - reference: PMID:28054173
    reference_title: "Association of AHSG with alopecia and mental retardation (APMR) syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Alopecia with mental retardation syndrome (APMR) is a very rare autosomal recessive condition that is associated with total or partial absence of hair from the scalp and other parts of the body as well as variable intellectual disability."
    explanation: States both the recessive inheritance pattern and the cardinal two-component phenotype.
  - reference: PMID:28054173
    reference_title: "Association of AHSG with alopecia and mental retardation (APMR) syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Here we present whole-exome sequencing results of a large consanguineous family segregating APMR syndrome with seven affected family members."
    explanation: Segregation across seven affected members of one consanguineous kindred is the basis for the recessive model.
prevalence:
- population: Worldwide
  measure_type: POINT_PREVALENCE
  prevalence_class: BELOW_1_IN_1000000
  rate_per_100000: 0.1
  notes: >-
    The estimate is for the APMR group as a whole, not for APMR1 specifically. APMR1
    itself is documented in a small number of consanguineous kindreds (predominantly
    Pakistani and Iranian) rather than by any formal epidemiological study.
  evidence:
  - reference: PMID:33881165
    reference_title: "Alopecia-mental retardation syndrome: Molecular genetics of a rare neuro-dermal disorder."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Its precise prevalence is still unknown, but according to a predictive estimate, it prevails with the ratio of 1 in 1,000,000 persons worldwide."
    explanation: Predictive prevalence estimate for the APMR group, supporting the BELOW_1_IN_1000000 class.
  - reference: PMID:33881165
    reference_title: "Alopecia-mental retardation syndrome: Molecular genetics of a rare neuro-dermal disorder."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "So far, approximately 14 families (i.e., Iranian, Pakistani, and Swiss) with APMR have been reported in the scientific literature."
    explanation: Quantifies the total reported APMR literature, supporting the ultra-rare classification.
mechanistic_hypotheses:
- hypothesis_group_id: fetuin_tgfb_antagonism_model
  hypothesis_label: Loss of fetuin-A TGF-beta antagonism model
  status: EMERGING
  description: >
    A candidate explanatory model in which the APMR1 phenotype follows from loss of
    fetuin-A's function as an antagonist of TGF-beta family signalling. Fetuin-A is a
    potent TGF-beta antagonist, and TGF-beta2 is the isoform that induces catagen (the
    regression phase) of the human hair cycle: in human hair follicle organ culture,
    adding fetuin markedly elongates follicles in a concentration-dependent manner.
    Reduced fetuin-A antagonism would therefore be expected to leave TGF-beta2 signalling
    unopposed in the follicle. AHSG is separately reported to be expressed in the fetal
    human brain and believed to be involved in embryonic neocortical development,
    offering a parallel route to the neurodevelopmental arm.

    This model is EMERGING, not canonical. Every step downstream of the AHSG variant is
    inferred from fetuin-A biology studied outside APMR1 — none of it has been shown in
    APMR1 patient tissue, and no functional rescue experiment has been reported for
    p.Arg317His.

    A concrete competing route exists and is not modelled here. Sailani et al., who
    identified the gene, proposed a more disease-specific mechanism: AHSG is expressed in
    developing hair follicles at the stage where basal keratinocytes reorganise into
    follicular placodes, is expressed more in fetal than postnatal skin, and promotes
    primary keratinocyte migration; a parallel argument places it in early neocortical
    neurons. That is a placode-formation and cell-migration model rather than a
    TGF-beta-antagonism one, and it may well be the better explanation. It is not curated
    as pathophysiology nodes because those observations sit in the paywalled full text of
    PMID:28054173, whose cache entry is abstract-only, so no verified snippet can support
    them, not because the evidence for them is weaker. See section 6 of
    research/Alopecia-Intellectual_Disability_Syndrome_1-deep-research-falcon.md.

    Two further possibilities are also unexcluded: that the phenotype arises from a
    fetuin-A function unrelated to any of these, or from a second variant in linkage
    disequilibrium within the run of homozygosity.
  evidence:
  - reference: PMID:12060393
    reference_title: "Involvement of transforming growth factor-beta2 in catagen induction during the human hair cycle."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "In the presence of the antibody as well as fetuin, hair follicles were markedly elongated in a concentration-dependent manner."
    explanation: >-
      Fetuin promotes human hair follicle elongation in organ culture, which is the
      observation the loss-of-antagonism model is built on.
  - reference: PMID:12853704
    reference_title: "Elevated levels of alpha-2-Heremans-Schmid glycoprotein in CSF of patients with low-grade gliomas."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "This glycoprotein is expressed in the fetal human brain and is believed to be involved in the embryonic development of the neocortex."
    explanation: >-
      Supports a plausible neurodevelopmental role for AHSG, but is a background
      statement in a glioma proteomics paper rather than a primary developmental result,
      so it is graded PARTIAL.
pathophysiology:
- name: Biallelic AHSG Missense Variant
  role: trigger
  biological_scale: MOLECULAR
  mechanism_confidence: PROVISIONAL
  description: >
    A homozygous missense variant in AHSG (NM_001622:exon7:c.950G>A, p.Arg317His) was
    identified by whole-exome sequencing as the candidate cause of APMR1. The residue
    lies in a region of the protein required for protein processing and the substitution
    disrupts a phosphorylation motif. AHSG maps within the previously reported APMR1
    linkage interval and the variant falls within a run of homozygosity.

    Confidence is PROVISIONAL rather than ESTABLISHED: the assertion rests on a single
    consanguineous family, a single predicted-pathogenic missense allele, and no
    reported functional rescue. No independent family with a second AHSG allele has been
    published, and ClinGen has not curated an AHSG gene-disease validity assertion.
  gene:
    preferred_term: AHSG
    term:
      id: hgnc:349
      label: AHSG
  evidence:
  - reference: PMID:28054173
    reference_title: "Association of AHSG with alopecia and mental retardation (APMR) syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Our study revealed a novel predicted pathogenic, homozygous missense mutation in the AHSG (OMIM 138680) gene (AHSG: NM_001622:exon7:c.950G>A:p.Arg317His)."
    explanation: Identifies the specific causal allele and its zygosity.
  - reference: PMID:28054173
    reference_title: "Association of AHSG with alopecia and mental retardation (APMR) syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Consistent with the phenotype, AHSG maps within APMR linkage region 1 (APMR 1) as reported before, and falls within runs of homozygosity (ROH)."
    explanation: Positional concordance with the independently mapped APMR1 locus supports the gene assignment.
  - reference: PMID:16273389
    reference_title: "Localization of a novel locus for alopecia with mental retardation syndrome to chromosome 3q26.33-q27.3."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Recombination events observed in affected individuals localized the disease locus between markers D3S1232 and D3S2436, spanning 11.49-cM region on chromosome 3q26.33-q27.3."
    explanation: The original linkage interval that AHSG was later found to lie within.
  downstream:
  - target: Aberrant Fetuin-A Protein Processing
    description: >-
      The substituted residue lies in a region required for protein processing and
      disrupts a phosphorylation motif, and the mutant protein migrates aberrantly.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:28054173
      reference_title: "Association of AHSG with alopecia and mental retardation (APMR) syndrome."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "The variant is predicted to affect a region of the protein required for protein processing and disrupts a phosphorylation motif."
      explanation: Predicts the proximal molecular consequence of the p.Arg317His substitution.
- name: Aberrant Fetuin-A Protein Processing
  biological_scale: MOLECULAR
  mechanism_confidence: PROVISIONAL
  description: >
    The p.Arg317His protein migrates with an aberrant size relative to that of healthy
    individuals, the only direct experimental evidence that the variant alters the
    protein product. Whether this reflects altered post-translational modification,
    reduced secretion, or reduced functional activity was not determined, and no
    quantitative assay of circulating fetuin-A in affected individuals has been reported.
  gene:
    preferred_term: AHSG
    term:
      id: hgnc:349
      label: AHSG
  evidence:
  - reference: PMID:28054173
    reference_title: "Association of AHSG with alopecia and mental retardation (APMR) syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "In addition, the altered protein migrates with an aberrant size relative to healthy individuals."
    explanation: Direct observation that the variant changes the fetuin-A protein product.
  downstream:
  - target: Reduced Fetuin-A TGF-beta Antagonism
    description: >-
      A processing-defective fetuin-A is postulated to provide less TGF-beta antagonism.
      This step is inferred, not measured, in APMR1.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    hypothesis_groups:
    - fetuin_tgfb_antagonism_model
    evidence:
    - reference: PMID:12060393
      reference_title: "Involvement of transforming growth factor-beta2 in catagen induction during the human hair cycle."
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: "Next, a neutralizing antibody and fetuin, a potent transforming growth factor-beta antagonist was tested."
      explanation: >-
        Establishes fetuin as a TGF-beta antagonist, the function whose loss this edge
        postulates; it does not itself demonstrate reduced antagonism in APMR1.
- name: Reduced Fetuin-A TGF-beta Antagonism
  biological_scale: MOLECULAR
  mechanism_confidence: HYPOTHETICAL
  description: >
    Fetuin-A is a potent antagonist of TGF-beta family signalling. The model proposes
    that a processing-defective fetuin-A antagonises TGF-beta less effectively, leaving
    TGF-beta signalling relatively unopposed in tissues that depend on fetuin-A for this
    restraint. No measurement of TGF-beta pathway activity has been reported in APMR1
    patient tissue, so this node is HYPOTHETICAL.
  biological_processes:
  - preferred_term: negative regulation of transforming growth factor beta receptor signaling pathway
    term:
      id: GO:0030512
      label: negative regulation of transforming growth factor beta receptor signaling pathway
    modifier: DECREASED
  evidence:
  - reference: PMID:8662721
    reference_title: "Fetuin/alpha2-HS glycoprotein is a transforming growth factor-beta type II receptor mimic and cytokine antagonist."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "Surface plasmon resonance measurements show that fetuin binds directly to TGF-beta1 and TGF-beta2 and with greater affinity to the TGF-beta-related bone morphogenetic proteins (BMP-2, BMP-4, and BMP-6)."
    explanation: >-
      Direct binding measurements establishing the ligand-sequestration mechanism of
      fetuin-A that this node describes losing.
  - reference: PMID:8662721
    reference_title: "Fetuin/alpha2-HS glycoprotein is a transforming growth factor-beta type II receptor mimic and cytokine antagonist."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "suggest that fetuin is a natural antagonist of TGF-beta and BMP activities"
    explanation: The authors' summary of fetuin as a physiological TGF-beta/BMP antagonist.
  - reference: PMID:12060393
    reference_title: "Involvement of transforming growth factor-beta2 in catagen induction during the human hair cycle."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "Next, a neutralizing antibody and fetuin, a potent transforming growth factor-beta antagonist was tested."
    explanation: Independent confirmation of the antagonist function, in the hair-follicle context.
  downstream:
  - target: Premature Hair Follicle Catagen Entry
    description: >-
      Unopposed TGF-beta2 signalling in the follicle is proposed to drive premature or
      persistent catagen entry.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    hypothesis_groups:
    - fetuin_tgfb_antagonism_model
    evidence:
    - reference: PMID:12060393
      reference_title: "Involvement of transforming growth factor-beta2 in catagen induction during the human hair cycle."
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: "These results strongly suggest that transforming growth factor-beta2 plays an essential part in the induction of the catagen phase of the human hair cycle."
      explanation: TGF-beta2 is the catagen-inducing signal that fetuin-A loss would leave unopposed.
  - target: Impaired Neocortical Development
    description: >-
      A parallel route to the neurodevelopmental arm, resting on AHSG expression in the
      fetal human brain rather than on any measurement in APMR1.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    hypothesis_groups:
    - fetuin_tgfb_antagonism_model
    evidence:
    - reference: PMID:12853704
      reference_title: "Elevated levels of alpha-2-Heremans-Schmid glycoprotein in CSF of patients with low-grade gliomas."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "This glycoprotein is expressed in the fetal human brain and is believed to be involved in the embryonic development of the neocortex."
      explanation: >-
        The only published statement placing AHSG in human neocortical development; it is
        an introductory claim in a glioma paper, hence PARTIAL.
- name: Premature Hair Follicle Catagen Entry
  biological_scale: TISSUE
  mechanism_confidence: HYPOTHETICAL
  description: >
    TGF-beta2 induces catagen, the regression phase of the human hair cycle: it is
    strongly immunoreactive in lower bulb matrix cells at the anagen-catagen transition
    and colocalises with its type II receptor in regressing epithelial strands
    containing apoptotic cells. Exogenous TGF-beta2 suppresses hair elongation in organ
    culture, while fetuin markedly elongates follicles. The model proposes that failure
    of fetuin-A antagonism shifts follicles toward catagen, but this has not been shown
    in APMR1 skin, and no scalp biopsy or follicle histology has been reported for an
    AHSG-variant patient.
  biological_processes:
  - preferred_term: hair follicle development
    term:
      id: GO:0001942
      label: hair follicle development
    modifier: DECREASED
  cell_types:
  - preferred_term: hair follicle cell
    term:
      id: CL:0002559
      label: hair follicle cell
  evidence:
  - reference: PMID:12060393
    reference_title: "Involvement of transforming growth factor-beta2 in catagen induction during the human hair cycle."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "Elongation of hair was significantly suppressed by transforming growth factor-beta2."
    explanation: Direct demonstration that TGF-beta2 suppresses human hair growth in organ culture.
  - reference: PMID:12060393
    reference_title: "Involvement of transforming growth factor-beta2 in catagen induction during the human hair cycle."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "During the anagen-catagen transition phase, strong transforming growth factor-beta2 immunoreactivity appeared in the lower bulb matrix cells adjacent to the dermal papilla."
    explanation: Localises the catagen-inducing TGF-beta2 signal to the follicle compartment.
  downstream:
  - target: Alopecia of Scalp
    description: >-
      Failure to sustain anagen manifests clinically as absent or sparse scalp hair.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    hypothesis_groups:
    - fetuin_tgfb_antagonism_model
    evidence:
    - reference: PMID:28054173
      reference_title: "Association of AHSG with alopecia and mental retardation (APMR) syndrome."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "associated with total or partial absence of hair from the scalp and other parts of the body"
      explanation: The clinical hair phenotype that the follicle-level node is proposed to produce.
- name: Impaired Neocortical Development
  biological_scale: TISSUE
  mechanism_confidence: HYPOTHETICAL
  description: >
    AHSG is reported to be expressed in the fetal human brain and believed to be involved
    in embryonic neocortical development. The model proposes that a processing-defective
    fetuin-A perturbs this role, producing the intellectual disability component. No
    neuroimaging series, neuropathology, or patient-derived neural model has been
    reported for AHSG-variant individuals, so the node rests entirely on background
    expression data from an unrelated study population.
  biological_processes:
  - preferred_term: cerebral cortex development
    term:
      id: GO:0021987
      label: cerebral cortex development
    modifier: ABNORMAL
  evidence:
  - reference: PMID:12853704
    reference_title: "Elevated levels of alpha-2-Heremans-Schmid glycoprotein in CSF of patients with low-grade gliomas."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "This glycoprotein is expressed in the fetal human brain and is believed to be involved in the embryonic development of the neocortex."
    explanation: >-
      The sole published basis for a neocortical role of AHSG; a background statement,
      not a primary developmental finding, so graded PARTIAL.
  downstream:
  - target: Intellectual Disability
    description: >-
      Disturbed neocortical development is proposed to underlie the variable intellectual
      disability.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    hypothesis_groups:
    - fetuin_tgfb_antagonism_model
    evidence:
    - reference: PMID:33881165
      reference_title: "Alopecia-mental retardation syndrome: Molecular genetics of a rare neuro-dermal disorder."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "absence of hair on the scalp, eyelashes, and eyebrows and mild to severe intellectual disability"
      explanation: The clinical neurodevelopmental phenotype the node is proposed to produce.
phenotypes:
- name: Alopecia of Scalp
  category: Clinical
  description: >
    Absence of scalp hair, total in some affected individuals and partial in others. This
    is the presenting feature and the one that names the disease. Onset is not
    established for APMR1: affected relatives were documented from age three onward, but
    no report gives an age at onset, so no structured onset descriptor is asserted here
    even though the sibling APMR4 entry records CONGENITAL onset for its own cohort.
  phenotype_term:
    preferred_term: Alopecia of scalp
    term:
      id: HP:0002293
      label: Alopecia of scalp
  frequency: OBLIGATE
  evidence:
  - reference: PMID:28054173
    reference_title: "Association of AHSG with alopecia and mental retardation (APMR) syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "associated with total or partial absence of hair from the scalp and other parts of the body"
    explanation: Documents the extent and distribution of the hair loss.
  - reference: PMID:33881165
    reference_title: "Alopecia-mental retardation syndrome: Molecular genetics of a rare neuro-dermal disorder."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "absence of hair on the scalp, eyelashes, and eyebrows and mild to severe intellectual disability"
    explanation: Confirms scalp involvement across the APMR series.
- name: Absent Eyebrow
  category: Clinical
  description: >
    Absence of the eyebrows accompanies the scalp alopecia. Note this differs from the
    sibling APMR4 entry, which curates SPARSE eyebrows (HP:0045075) because its own
    sources describe sparse rather than absent hair; the APMR literature describes
    absence, so the absent term is bound here.
  phenotype_term:
    preferred_term: Absent eyebrow
    term:
      id: HP:0002223
      label: Absent eyebrow
  evidence:
  - reference: PMID:17451405
    reference_title: "Mapping of a gene for alopecia with mental retardation syndrome (APMR3) on chromosome 18q11.2-q12.2."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Affected individuals with APMR syndrome show loss of hair on the scalp, absence of eyebrows, eyelashes, axillary and pubic hair, and mild to severe mental retardation."
    explanation: States absence of eyebrows as a feature of the APMR phenotype.
  - reference: PMID:33881165
    reference_title: "Alopecia-mental retardation syndrome: Molecular genetics of a rare neuro-dermal disorder."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "absence of hair on the scalp, eyelashes, and eyebrows and mild to severe intellectual disability"
    explanation: Independent review confirming eyebrow involvement.
- name: Absent Eyelashes
  category: Clinical
  description: >
    Absence of the eyelashes accompanies the scalp alopecia.
  phenotype_term:
    preferred_term: Absent eyelashes
    term:
      id: HP:0000561
      label: Absent eyelashes
  evidence:
  - reference: PMID:17451405
    reference_title: "Mapping of a gene for alopecia with mental retardation syndrome (APMR3) on chromosome 18q11.2-q12.2."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Affected individuals with APMR syndrome show loss of hair on the scalp, absence of eyebrows, eyelashes, axillary and pubic hair, and mild to severe mental retardation."
    explanation: States absence of eyelashes as a feature of the APMR phenotype.
  - reference: PMID:33881165
    reference_title: "Alopecia-mental retardation syndrome: Molecular genetics of a rare neuro-dermal disorder."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "absence of hair on the scalp, eyelashes, and eyebrows and mild to severe intellectual disability"
    explanation: Independent review confirming eyelash involvement.
- name: Absent Axillary Hair
  category: Clinical
  description: >
    Absence of axillary hair extends the hair phenotype beyond the head. Because this is
    post-pubertal hair, it is assessable only in older affected individuals, and no
    report separates how many of them were of an age to show it.
  phenotype_term:
    preferred_term: Absent axillary hair
    term:
      id: HP:0002221
      label: Absent axillary hair
  evidence:
  - reference: PMID:17451405
    reference_title: "Mapping of a gene for alopecia with mental retardation syndrome (APMR3) on chromosome 18q11.2-q12.2."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Affected individuals with APMR syndrome show loss of hair on the scalp, absence of eyebrows, eyelashes, axillary and pubic hair, and mild to severe mental retardation."
    explanation: States absence of axillary hair as a feature of the APMR phenotype.
- name: Absent Pubic Hair
  category: Clinical
  description: >
    Absence of pubic hair extends the hair phenotype to a second post-pubertal site,
    subject to the same age-assessability caveat as axillary hair.
  phenotype_term:
    preferred_term: Absent pubic hair
    term:
      id: HP:0002555
      label: Absent pubic hair
  evidence:
  - reference: PMID:17451405
    reference_title: "Mapping of a gene for alopecia with mental retardation syndrome (APMR3) on chromosome 18q11.2-q12.2."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Affected individuals with APMR syndrome show loss of hair on the scalp, absence of eyebrows, eyelashes, axillary and pubic hair, and mild to severe mental retardation."
    explanation: States absence of pubic hair as a feature of the APMR phenotype.
- name: Intellectual Disability
  category: Clinical
  description: >
    Intellectual disability of variable degree, reported across the APMR series as ranging
    from mild to severe. Severity is not uniform across the families that define APMR1:
    the original 3q26.33-q27.3 linkage family was described as severely affected, while
    a 2024 comparative study (PMID:38800572) characterises APMR1 as mild-to-moderate.
    Since only the AHSG-solved family has a molecular diagnosis, it is not established
    that both families represent the same genetic entity. Formal cognitive testing data
    exist - the Edison deep-research run reports Stanford-Binet IQ 40-54 across all seven
    affected relatives of the AHSG family - but sit in the paywalled full text of
    PMID:28054173, whose cache entry is abstract-only, so they cannot be carried as a
    verified snippet and the range is curated qualitatively. See
    research/Alopecia-Intellectual_Disability_Syndrome_1-deep-research-falcon.md.
  phenotype_term:
    preferred_term: Intellectual disability
    term:
      id: HP:0001249
      label: Intellectual disability
  frequency: OBLIGATE
  evidence:
  - reference: PMID:28054173
    reference_title: "Association of AHSG with alopecia and mental retardation (APMR) syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "as well as variable intellectual disability"
    explanation: Documents the neurodevelopmental component and its variability.
  - reference: PMID:33881165
    reference_title: "Alopecia-mental retardation syndrome: Molecular genetics of a rare neuro-dermal disorder."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "mild to severe intellectual disability"
    explanation: Gives the reported severity range across the APMR series.
  - reference: PMID:17451405
    reference_title: "Mapping of a gene for alopecia with mental retardation syndrome (APMR3) on chromosome 18q11.2-q12.2."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Affected individuals with APMR syndrome show loss of hair on the scalp, absence of eyebrows, eyelashes, axillary and pubic hair, and mild to severe mental retardation."
    explanation: >-
      Gives the full hair distribution (including axillary and pubic hair) alongside the
      mild-to-severe cognitive range for the APMR series.
genetic:
- name: AHSG
  gene_term:
    preferred_term: AHSG
    term:
      id: hgnc:349
      label: AHSG
  relationship_type: CAUSATIVE
  presence: PRESENT
  variant_origin: GERMLINE
  variants:
  - name: 'NM_001622:c.950G>A (p.Arg317His)'
    identifiers:
    - dbSNP:rs201849460
    description: >-
      Germline homozygous missense substitution in AHSG exon 7, reported as predicted
      pathogenic, affecting a region required for protein processing and disrupting a
      phosphorylation motif. Curated as LIKELY_PATHOGENIC rather than PATHOGENIC: the
      supporting data are segregation in one consanguineous family plus in silico
      prediction, with the only experimental readout an altered protein migration on
      Western blot. No functional assay establishes the direction of effect, so whether
      the allele is loss-of-function, dominant-negative, or neomorphic is unresolved.
      A simple loss-of-function reading is actively disfavoured by the human allelic
      series: a homozygous AHSG nonsense allele (p.Lys2Ter) causing complete fetuin-A
      deficiency on ELISA has been reported to cause infantile cortical hyperostosis
      (Caffey disease), not alopecia with intellectual disability. If total absence of
      fetuin-A gives a skeletal phenotype, p.Arg317His is unlikely to act by simple
      absence of protein.
      Note that the schema's ClinicalSignificanceEnum offers no uncertain-significance
      (VUS) tier, so LIKELY_PATHOGENIC is the closest available grade rather than an
      exact reflection of the ACMG evidence here.
    gene:
      preferred_term: AHSG
      term:
        id: hgnc:349
        label: AHSG
    type: missense
    clinical_significance: LIKELY_PATHOGENIC
    evidence:
    - reference: PMID:28054173
      reference_title: "Association of AHSG with alopecia and mental retardation (APMR) syndrome."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Our study revealed a novel predicted pathogenic, homozygous missense mutation in the AHSG (OMIM 138680) gene (AHSG: NM_001622:exon7:c.950G>A:p.Arg317His)."
      explanation: The primary report of the allele, its zygosity, and its predicted pathogenicity.
  evidence:
  - reference: PMID:33881165
    reference_title: "Alopecia-mental retardation syndrome: Molecular genetics of a rare neuro-dermal disorder."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Among them, AHSG was reported in a consanguineous Iranian family and LSS gene in a Swiss origin family, while the remaining two uncharacterized loci, that is, APMR2 and APMR3, are reported in the Pakistani population."
    explanation: >-
      Independent review confirming AHSG as the APMR1 gene and, importantly, that only
      APMR1 and APMR4 are molecularly characterised.
  - reference: PMID:28054173
    reference_title: "Association of AHSG with alopecia and mental retardation (APMR) syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Our study is the first report to identify a homozygous missense mutation for APMR syndrome through whole-exome sequencing."
    explanation: >-
      The authors' own framing as a first report is the reason this gene-disease
      assertion is curated as PROVISIONAL rather than ESTABLISHED.
  notes: >-
    AHSG (alpha-2-HS-glycoprotein, fetuin-A) at 3q27.3 is the causal gene assigned to
    APMR1. The assignment rests on a single homozygous missense allele, p.Arg317His,
    identified by whole-exome sequencing in one large consanguineous family with seven
    affected members, supported by positional concordance with the independently mapped
    3q26.33-q27.3 linkage interval and by aberrant migration of the mutant protein.

    Do NOT attribute LSS to APMR1. LSS (21q22.3) causes APMR4, a different disease on a
    different chromosome. Do NOT attribute the HR (hairless) gene to APMR1 either: HR is
    at 8p21.3 and causes atrichia with papular lesions, a separate condition in the
    differential. Both conflations appear in secondary sources describing this numbered
    series and are the documented Named Entity Confusion risk for this target.
animal_models:
- name: Ahsg-null mouse
  species: Mouse
  genotype: Ahsg-/- (targeted null)
  background: C57BL/6 and DBA/2
  publication: PMID:12897203
  description: >
    The constitutive Ahsg knockout mouse was generated and characterised as a model of
    ectopic calcification, not of APMR1. It is reported as phenotypically normal at
    baseline, developing severe organ calcification only on a mineral- and vitamin
    D-rich diet or on a DBA/2 background. No alopecia or neurodevelopmental phenotype is
    reported.
  genes:
  - preferred_term: AHSG
    term:
      id: hgnc:349
      label: AHSG
  modeled_mechanisms:
  - target: Premature Hair Follicle Catagen Entry
    relationship: FAILS_TO_RECAPITULATE
    fidelity: LOW
    description: >-
      Complete loss of Ahsg in the mouse does not produce the hair phenotype that a
      human biallelic AHSG variant produces, which is the central difficulty for any
      loss-of-function model of APMR1.
    limitations: >-
      The report is a calcification study and did not set out to phenotype hair or
      behaviour, so "phenotypically normal" is a general statement rather than the
      result of a targeted dermatological or neurodevelopmental assessment; absence of a
      reported hair phenotype is therefore weaker than a documented negative. Two
      further caveats apply: the human allele is a missense substitution rather than a
      null, so a mouse null is not the matched genotype and a dominant-negative or
      neomorphic mechanism would not be modelled by it; and mouse and human hair-cycle
      biology differ, with the human catagen data underpinning this node coming from
      human follicle organ culture rather than mouse.
    evidence:
    - reference: PMID:12897203
      reference_title: "The serum protein alpha 2-Heremans-Schmid glycoprotein/fetuin-A is a systemically acting inhibitor of ectopic calcification."
      supports: REFUTE
      evidence_source: MODEL_ORGANISM
      snippet: "Ahsg-deficient mice are phenotypically normal, but develop severe calcification of various organs on a mineral and vitamin D-rich diet and on a normal diet when the deficiency is combined with a DBA/2 genetic background."
      explanation: >-
        A constitutive Ahsg null is reported as otherwise phenotypically normal, so the
        mouse does not reproduce the human hair phenotype.
  evidence:
  - reference: PMID:12897203
    reference_title: "The serum protein alpha 2-Heremans-Schmid glycoprotein/fetuin-A is a systemically acting inhibitor of ectopic calcification."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "Taken together, our data demonstrate a critical role of Ahsg as an inhibitor of unwanted mineralization"
    explanation: >-
      Establishes what the Ahsg-null mouse does model — systemic calcification control —
      which is not the APMR1 phenotype.
  notes: >-
    Listed because its negative result constrains the mechanism model, not because it is
    a validated APMR1 model. No mouse carrying the orthologous p.Arg317His substitution
    has been reported.
treatments:
- name: Supportive and Developmental Care
  description: >
    There is no disease-modifying therapy for APMR1 and no interventional trial has ever
    been registered. Management is supportive and multidisciplinary: early developmental
    intervention and special education for the intellectual disability, with speech,
    occupational and physical therapy as needed, plus dermatological care of the
    hairless scalp (sun protection, scalp care, and hair prostheses where wanted).
  treatment_term:
    preferred_term: Supportive Care
    term:
      id: NCIT:C15747
      label: Supportive Care
  therapeutic_modality: BEHAVIORAL
  notes: >-
    Carried with no evidence block, following the same convention as the sibling APMR4
    entry: this is standard clinical practice for a neurodevelopmental syndrome rather
    than a finding any paper reports, and manufacturing a snippet for it would be worse
    than recording it as convention. The Edison deep-research run searched for a
    management guideline and found none.
- name: Genetic Counseling
  description: >
    Genetic counselling is the one intervention with a concrete, actionable basis in
    APMR1. The disorder is autosomal recessive and every reported family is
    consanguineous, so recurrence risk and cascade carrier testing are the practical
    questions families face. Testing is possible because the causal allele is known in
    the one solved family.
  treatment_term:
    preferred_term: Genetic Counseling
    term:
      id: NCIT:C15240
      label: Genetic Counseling
  evidence:
  - reference: PMID:28054173
    reference_title: "Association of AHSG with alopecia and mental retardation (APMR) syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Here we present whole-exome sequencing results of a large consanguineous family segregating APMR syndrome with seven affected family members."
    explanation: >-
      Consanguinity and recessive segregation in a large kindred are what make recurrence
      counselling and cascade testing the relevant intervention.
diagnosis:
- name: Molecular genetic testing
  description: >-
    APMR1 is confirmed by identifying biallelic pathogenic AHSG variants. The gene was
    itself discovered by whole-exome sequencing, and in practice a clinical diagnosis of
    congenital alopecia with intellectual disability is resolved to a numbered APMR form
    only by sequencing, since the four forms are clinically overlapping and are separated
    by gene rather than by phenotype.
  diagnosis_term:
    preferred_term: molecular genetic testing
    term:
      id: NCIT:C15709
      label: Genetic Testing
  results: Biallelic pathogenic AHSG variants confirming APMR1.
  evidence:
  - reference: PMID:28054173
    reference_title: "Association of AHSG with alopecia and mental retardation (APMR) syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Our study is the first report to identify a homozygous missense mutation for APMR syndrome through whole-exome sequencing."
    explanation: Establishes exome sequencing as the route by which an APMR1 diagnosis is made.
  - reference: PMID:28054173
    reference_title: "Association of AHSG with alopecia and mental retardation (APMR) syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Previous families with APMR syndrome have been studied through linkage analyses and the linkage resolution did not allow pointing out to a single gene candidate."
    explanation: >-
      Explains why sequencing rather than linkage is the diagnostic route: linkage
      localises but does not identify the gene.
  notes: >-
    Serum fetuin-A electrophoresis is deliberately NOT curated as a diagnostic test. The
    aberrant migration of the mutant protein is a single research observation in one
    family, with no reported sensitivity, specificity, reference interval, or independent
    replication, and the deep-research run classified it as research-level rather than a
    validated clinical assay. Promoting it to `diagnosis:` would overstate it.
differential_diagnoses:
- name: Alopecia-Intellectual Disability Syndrome 4
  description: >-
    APMR4, caused by biallelic LSS variants at 21q22.3, presents with the same core
    combination of congenital alopecia and intellectual disability and is the main
    within-series differential. It is distinguished by frequent early-onset epilepsy and
    additional dermatological features, and is separated definitively by gene testing.
  disease_term:
    preferred_term: alopecia-intellectual disability syndrome 4
    term:
      id: MONDO:0030009
      label: alopecia-intellectual disability syndrome 4
  evidence:
  - reference: PMID:33881165
    reference_title: "Alopecia-mental retardation syndrome: Molecular genetics of a rare neuro-dermal disorder."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Among them, AHSG was reported in a consanguineous Iranian family and LSS gene in a Swiss origin family"
    explanation: Establishes APMR1 and APMR4 as distinct gene-defined entities within the series.
- name: Infantile Cortical Hyperostosis (Caffey Disease)
  description: >-
    Not a clinical mimic but the key allelic comparator. A homozygous AHSG nonsense
    variant (c.A4T, p.Lys2Ter) producing complete serum fetuin-A deficiency has been
    reported in an infant with classical infantile cortical hyperostosis — subperiosteal
    bone hyperplasia, with no alopecia or intellectual disability described. The
    autosomal dominant form of Caffey disease is caused by COL1A1. Because a human AHSG
    null gives a skeletal rather than a neurocutaneous phenotype, the APMR1 missense
    allele is unlikely to act by simple loss of protein; this is the strongest available
    constraint on the APMR1 mechanism and is stronger than the mouse knockout evidence
    because it is human. Note the term binding: MONDO:0007244 is the clinical Caffey
    disease concept, which is predominantly the autosomal dominant COL1A1 entity. MONDO
    has no class for the AHSG-related recessive form, so the binding here is to the
    clinical entity rather than to the specific allelic condition described.
  disease_term:
    preferred_term: infantile cortical hyperostosis
    term:
      id: MONDO:0007244
      label: Caffey disease
  evidence:
  - reference: PMID:31288248
    reference_title: "Fetuin-A deficiency is associated with infantile cortical hyperostosis (Caffey disease)."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "WES analysis revealed a novel homozygous nonsense mutation in lysine 2 of fetuin-A, encoded by the ALPHA-2-HS-GLYCOPROTEIN (AHSG) gene (c.A4T; p.K2X)."
    explanation: Identifies the human AHSG null allele and the disease it causes.
  - reference: PMID:31288248
    reference_title: "Fetuin-A deficiency is associated with infantile cortical hyperostosis (Caffey disease)."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "By enzyme-linked immunosorbent assay (ELISA), we show a complete deficiency of this protein in the patient's serum, compared to controls."
    explanation: >-
      Confirms the allele produces complete fetuin-A deficiency, which is what makes the
      phenotypic contrast with APMR1 informative.
- name: Atrichia with Papular Lesions
  description: >-
    HR-related atrichia with papular lesions also presents with near-total congenital
    hair loss but is caused by variants in HR at 8p21.3, is not accompanied by
    intellectual disability as a defining feature, and shows characteristic follicular
    papules. It is named here explicitly because the HR gene has been erroneously
    attributed to APMR1 in secondary sources.
  disease_term:
    preferred_term: atrichia with papular lesions
    term:
      id: MONDO:0008847
      label: atrichia with papular lesions
  evidence:
  - reference: PMID:33881165
    reference_title: "Alopecia-mental retardation syndrome: Molecular genetics of a rare neuro-dermal disorder."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The current mini-report discusses the molecular genetics and mutational spectrum of APMR syndrome, its differential diagnosis from related disorders"
    explanation: >-
      The cited review is the source that works through the APMR differential; the
      specific HR distinction is recorded in the description rather than quoted.
discussions:
- discussion_id: apmr1_ahsg_gene_validity
  prompt: >-
    Is AHSG established as the APMR1 gene, given that the assignment rests on one
    consanguineous family, one predicted-pathogenic missense allele, and no functional
    rescue?
  kind: KNOWLEDGE_GAP
  status: OPEN
  attaches_to:
  - pathophysiology#Biallelic AHSG Missense Variant
  - genetic#AHSG
  rationale: >-
    The AHSG assignment has real positional support: the gene lies inside the
    independently mapped 3q26.33-q27.3 interval and within a run of homozygosity, and
    the mutant protein migrates aberrantly. But it is a single-family, single-allele
    report from 2017 and, as of this curation, no second family with an independent AHSG
    allele has been published, no functional assay establishes the direction of effect,
    and ClinGen has curated no gene-disease validity assertion for AHSG. The Ahsg-null
    mouse being phenotypically normal cuts against a simple loss-of-function model. The
    entry therefore records mechanism_confidence PROVISIONAL on the trigger node and
    PROVISIONAL on the trigger node and LIKELY_PATHOGENIC rather than PATHOGENIC on the
    variant. A further complication, surfaced by the Edison deep-research run: a
    different homozygous AHSG allele — the nonsense p.Lys2Ter, with complete serum
    fetuin-A deficiency confirmed by ELISA — has been reported to cause infantile
    cortical hyperostosis rather than APMR1. Two AHSG genotypes, two unrelated
    phenotypes, one family each. This is either an allelic series in which the missense
    acts by a non-null mechanism, or a sign that one of the two assignments is wrong.
    Resolving it needs a second unrelated APMR1 family or a functional readout, not more
    reviews restating the 2017 result.
  evidence:
  - reference: PMID:28054173
    reference_title: "Association of AHSG with alopecia and mental retardation (APMR) syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Previous families with APMR syndrome have been studied through linkage analyses and the linkage resolution did not allow pointing out to a single gene candidate."
    explanation: >-
      The authors note that prior linkage work could not resolve a single candidate,
      underlining that this is the first and so far only gene-level report.
  - reference: PMID:31288248
    reference_title: "Fetuin-A deficiency is associated with infantile cortical hyperostosis (Caffey disease)."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "A novel homozygous nonsense mutation in AHSG gene has been found in ICH patient with a typical phenotype, resulting in fetuin-A deficiency."
    explanation: >-
      A second, independent biallelic AHSG genotype associated with an entirely different
      phenotype, which complicates the APMR1 gene-disease assertion.
- discussion_id: apmr1_ahsg_mouse_mismatch
  prompt: >-
    Why is the Ahsg-null mouse phenotypically normal when biallelic human AHSG variants
    cause alopecia and intellectual disability?
  kind: HUMAN_MODEL_MISMATCH
  status: OPEN
  attaches_to:
  - pathophysiology#Reduced Fetuin-A TGF-beta Antagonism
  - animal_models#Mouse
  rationale: >-
    Model-system evidence for AHSG exists and is substantial, but it is about the wrong
    thing: the Ahsg-null mouse was built and characterised as a calcification model and
    is otherwise reported as phenotypically normal, with no hair or neurodevelopmental
    phenotype. This is a genuine mismatch rather than merely missing evidence, and it
    admits at least three readings that current data cannot separate. First, the human
    allele is a missense, not a null, so APMR1 may act by a dominant-negative or
    neomorphic mechanism that a knockout cannot model. Second, mouse and human may
    differ in how far hair-follicle cycling and cortical development depend on
    fetuin-A — notably, the human catagen evidence underpinning this model comes from
    human follicle organ culture, not mouse. Third, the mouse may simply never have been
    examined for the relevant phenotypes, since the study's endpoints were mineral.

    The human allelic series makes the first reading the most likely one. A homozygous
    AHSG nonsense allele with ELISA-confirmed complete fetuin-A deficiency causes
    infantile cortical hyperostosis, not APMR1 — so in humans, as in mice, absence of
    fetuin-A does not produce alopecia with intellectual disability. That converts the
    mouse result from an awkward species difference into a consistent cross-species
    signal that APMR1 is not a simple null phenotype. Until an allele-specific model
    exists, every node downstream of the variant stays HYPOTHETICAL.
  proposed_experiments:
  - experiment_id: apmr1_ahsg_ko_targeted_phenotyping
    name: Targeted dermatological and neurobehavioural phenotyping of Ahsg-/- mice
    description: >-
      Phenotype an existing Ahsg-null line specifically for hair-cycle staging (anagen/
      catagen distribution on synchronised depilation), follicle histology, and standard
      neurobehavioural and cortical-layering assays, rather than relying on the absence
      of a reported phenotype in a calcification study.
    would_support:
    - pathophysiology#Premature Hair Follicle Catagen Entry
    supporting_outcome:
    - >-
      Ahsg-/- mice show accelerated catagen entry after depilation-synchronised anagen,
      reduced follicle length, or cortical layering abnormalities.
    would_refute:
    - pathophysiology#Reduced Fetuin-A TGF-beta Antagonism
    refuting_outcome:
    - >-
      Systematic hair-cycle staging and neurobehavioural testing find no difference from
      wild-type, indicating that simple loss of fetuin-A is insufficient and directing
      attention to an allele-specific mechanism.
  - experiment_id: apmr1_ahsg_r317h_knockin
    name: Knock-in mouse carrying the orthologous p.Arg317His allele
    description: >-
      Generate a knock-in of the orthologous Ahsg missense substitution rather than a
      null, to test whether the human phenotype depends on the specific allele rather
      than on absence of the protein.
    would_support:
    - pathophysiology#Biallelic AHSG Missense Variant
    supporting_outcome:
    - >-
      Homozygous knock-in mice develop hair loss and/or cognitive impairment that the
      null does not, supporting an allele-specific (dominant-negative or neomorphic)
      mechanism.
    would_refute:
    - pathophysiology#Biallelic AHSG Missense Variant
    refuting_outcome:
    - >-
      Homozygous knock-in mice are indistinguishable from both wild-type and Ahsg-null
      mice, which would weaken the case for AHSG as the causal gene and revive the
      possibility of another variant within the run of homozygosity.
  evidence:
  - reference: PMID:12897203
    reference_title: "The serum protein alpha 2-Heremans-Schmid glycoprotein/fetuin-A is a systemically acting inhibitor of ectopic calcification."
    supports: REFUTE
    evidence_source: MODEL_ORGANISM
    snippet: "Ahsg-deficient mice are phenotypically normal, but develop severe calcification of various organs on a mineral and vitamin D-rich diet and on a normal diet when the deficiency is combined with a DBA/2 genetic background."
    explanation: The negative mouse result that creates the mismatch.
  - reference: PMID:31288248
    reference_title: "Fetuin-A deficiency is associated with infantile cortical hyperostosis (Caffey disease)."
    supports: REFUTE
    evidence_source: HUMAN_CLINICAL
    snippet: "By enzyme-linked immunosorbent assay (ELISA), we show a complete deficiency of this protein in the patient's serum, compared to controls."
    explanation: >-
      A human with no fetuin-A at all has a skeletal phenotype, not APMR1, which refutes
      the simple loss-of-function reading in the species that matters.
- discussion_id: apmr1_locus_series_confusion
  prompt: >-
    Which gene belongs to which numbered APMR form, and how should the series be modelled
    in dismech?
  kind: INTERPRETATION
  status: RESOLVED
  attaches_to:
  - disease#Alopecia-Intellectual Disability Syndrome 1
  rationale: >-
    Secondary sources describing this numbered series have attributed LSS to APMR1 and to
    APMR3, and have introduced an "HR locus" that belongs to a different disease
    entirely. Tracing the primary papers separates them cleanly: APMR1 maps to
    3q26.33-q27.3 with AHSG at 3q27.3; APMR2 maps to a distinct, non-overlapping
    3q26.2-q26.31 interval; APMR3 maps to chromosome 18q11.2-q12.2, nowhere near LSS; and
    LSS is at 21q22.3 and belongs to APMR4 only. Because the four forms have different
    genes on different chromosomes, they are separate diseases and the series is modelled
    as a Grouping over member Disease entries rather than as one Disease with
    has_subtypes.
  resolution_note: >-
    Resolved for this entry by curating APMR1 as its own Disease bound to MONDO:0021035
    and creating kb/groupings/Alopecia-Intellectual_Disability_Syndromes.yaml as the
    union over APMR1 and APMR4. APMR2 and APMR3 stay uncurated because they have no gene.
  evidence:
  - reference: PMID:16922726
    reference_title: "A novel locus for alopecia with mental retardation syndrome (APMR2) maps to chromosome 3q26.2-q26.31."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The linkage interval of the APMR locus identified here does not overlap with the one described previously; therefore, this locus has been designated as APMR2."
    explanation: Establishes APMR2 as a locus distinct from and non-overlapping with APMR1.
  - reference: PMID:33881165
    reference_title: "Alopecia-mental retardation syndrome: Molecular genetics of a rare neuro-dermal disorder."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "while the remaining two uncharacterized loci, that is, APMR2 and APMR3, are reported in the Pakistani population"
    explanation: Confirms APMR2 and APMR3 have no assigned gene, so neither can be curated as a Disease.
references:
- reference: PMID:28054173
  title: "Association of AHSG with alopecia and mental retardation (APMR) syndrome."
  found_in:
  - Alopecia-Intellectual_Disability_Syndrome_1-deep-research-falcon.md
- reference: PMID:31288248
  title: "Fetuin-A deficiency is associated with infantile cortical hyperostosis (Caffey disease)."
  found_in:
  - Alopecia-Intellectual_Disability_Syndrome_1-deep-research-falcon.md
- reference: PMID:8662721
  title: "Fetuin/alpha2-HS glycoprotein is a transforming growth factor-beta type II receptor mimic and cytokine antagonist."
notes: >-
  Curated against issue #8364, which targeted the APMR root (MONDO:0008756) as
  CURATE_ROOT_WITH_SUBTYPES. That instruction was not followed literally: the four
  numbered forms have different genes on different chromosomes, so has_subtypes would
  assert a single-gene severity spectrum that does not exist. The root is modelled as a
  Grouping instead, in line with the modelling note already recorded in the APMR4 entry.

  The issue body's gene hints ("APMR1 (LSS/HR locus, 3q26-q27) ... APMR3 (LSS)") are
  incorrect and were not used. See the apmr1_locus_series_confusion discussion for the
  primary-source trace.
📚

References & Deep Research

References

3
PMID:28054173
Association of AHSG with alopecia and mental retardation (APMR) syndrome.
No top-level findings curated for this source.
PMID:31288248
Fetuin-A deficiency is associated with infantile cortical hyperostosis (Caffey disease).
No top-level findings curated for this source.
PMID:8662721
Fetuin/alpha2-HS glycoprotein is a transforming growth factor-beta type II receptor mimic and cytokine antagonist.
No top-level findings curated for this source.

Deep Research

1
Falcon ▸
Disease Characteristics Research Template
Edison Scientific Literature 19 citations 2026-08-26T08:48:51.216269

Question: You are an expert researcher providing comprehensive, well-cited information.

Provide detailed information focusing on: 1. Key concepts and definitions with current understanding 2. Recent developments and latest research (prioritize 2023-2024 sources) 3. Current applications and real-world implementations 4. Expert opinions and analysis from authoritative sources 5. Relevant statistics and data from recent studies

Format as a comprehensive research report with proper citations. Include URLs and publication dates where available. Always prioritize recent, authoritative sources and provide specific citations for all major claims.

Disease Characteristics Research Template

Target Disease

  • Disease Name: Alopecia-Intellectual Disability Syndrome 1
  • MONDO ID: (if available)
  • Category: Mendelian

Research Objectives

Please provide a comprehensive research report on Alopecia-Intellectual Disability Syndrome 1 covering all of the disease characteristics listed below. This report will be used to populate a disease knowledge base entry. Be thorough and cite primary literature (PMID preferred) for all claims.

For each section, suggested databases/resources are listed. These are the first places you should search for information on each topic.

1. Disease Information

Search first: OMIM, Orphanet, ICD-10/ICD-11, MeSH, PubMed

  • What is the disease? Provide a concise overview.
  • What are the key identifiers? (OMIM, Orphanet, ICD-10/ICD-11, MeSH, Mondo)
  • What are the common synonyms and alternative names?
  • Is the information derived from individual patients (e.g., EHR) or aggregated disease-level resources?

2. Etiology

  • Disease Causal Factors: What are the primary causes? (genetic, environmental, infectious, mechanistic)
  • Risk Factors:

    Search first: PubMed, Cochrane Library, UpToDate, clinical guidelines, ClinVar, ClinGen, GWAS Catalog, PheGenI, CTD, CDC, WHO, epidemiological databases

  • Genetic risk factors (causal variants, susceptibility loci, modifier genes)
  • Environmental risk factors (toxins, lifestyle, occupational exposures, age, sex, family history)
  • Protective Factors:

    Search first: PubMed, Cochrane Library, clinical trial databases, GWAS Catalog, gnomAD, WHO, CDC, nutrition databases

  • Genetic protective factors (protective variants, modifier alleles)
  • Environmental protective factors (diet, lifestyle, exposures that reduce risk)
  • Gene-Environment Interactions: How do genetic and environmental factors interact to influence disease?

    Search first: CTD, PubMed, PheGenI, GxE databases

3. Phenotypes

Search first: HPO (Human Phenotype Ontology), OMIM, Orphanet, PubMed, clinicaltrials.gov, MedDRA, SNOMED CT, DECIPHER, LOINC

For each phenotype, provide: - Phenotype type: symptoms, clinical signs, physical manifestations, behavioral changes, or laboratory abnormalities

For symptoms/signs: HPO, OMIM, Orphanet, PubMed For behavioral changes: HPO, DSM, RDoC (Research Domain Criteria), PubMed For laboratory abnormalities: LOINC, SNOMED CT, LabTests Online, PubMed - Phenotype characteristics: Search first: OMIM, Orphanet, HPO, PubMed - Age of symptom onset (neonatal, childhood, adult-onset, late-onset) - Symptom severity (mild, moderate, severe, variable) - Symptom progression (stable, progressive, episodic, fluctuating) - Frequency among affected individuals (percentage or qualitative) - Quality of life impact: Effects on daily functioning and well-being (per-phenotype when possible) Search first: EQ-5D database, SF-36, WHO QOL databases, PubMed - Suggest HPO (Human Phenotype Ontology) terms for each phenotype

4. Genetic/Molecular Information

  • Causal Genes: Gene mutations or chromosomal abnormalities responsible for disease (gene symbols, OMIM IDs)

    Search first: OMIM, ClinVar, HGMD, Ensembl, NCBI Gene

  • Pathogenic Variants:
  • Affected genes (gene symbols, HGNC IDs) > Search first: OMIM, NCBI Gene, Ensembl, HGNC, UniProt, GeneCards
  • Variant classification (pathogenic, likely pathogenic, VUS per ACMG/AMP guidelines) > Search first: ClinVar, ClinGen, ACMG/AMP guidelines, VarSome
  • Variant type/class (missense, frameshift, nonsense, splice-site, structural)
  • Allele frequency in population databases > Search first: gnomAD, 1000 Genomes, ExAC, TOPMed, dbSNP
  • Somatic vs germline origin > Search first: COSMIC (somatic), ClinVar, ICGC, TCGA
  • Functional consequences (loss of function, gain of function, dominant negative)
  • Modifier Genes: Genes that modify disease severity or expression
  • Epigenetic Information: DNA methylation, histone modifications, chromatin changes affecting disease

    Search first: ENCODE, Roadmap Epigenomics, MethBase, DiseaseMeth

  • Chromosomal Abnormalities: Large-scale genetic changes (aneuploidy, translocations, inversions)

    Search first: DECIPHER, ClinVar, ECARUCA, UCSC Genome Browser

5. Environmental Information

  • Environmental Factors: Non-genetic contributing factors (toxins, radiation, pollution, occupational exposure)

    Search first: CTD (Comparative Toxicogenomics Database), TOXNET, PubMed, EPA databases

  • Lifestyle Factors: Behavioral factors (smoking, diet, exercise, alcohol consumption)

    Search first: CDC databases, WHO, PubMed, NHANES

  • Infectious Agents: If applicable, pathogens causing or triggering disease (bacteria, viruses, fungi, parasites)

    Search first: NCBI Taxonomy, ViPR, BV-BRC, MicrobeDB, GIDEON

6. Mechanism / Pathophysiology

  • Molecular Pathways: Specific signaling cascades or biochemical pathways involved (Wnt, MAPK, mTOR, PI3K-AKT, etc.)

    Search first: KEGG, Reactome, WikiPathways, PathBank, BioCyc

  • Cellular Processes: Cell-level mechanisms (apoptosis, autophagy, cell cycle dysregulation, inflammation, etc.)

    Search first: Gene Ontology (GO), Reactome, KEGG, PubMed

  • Protein Dysfunction: How protein structure or function is altered (misfolding, aggregation, loss of function, gain of function)

    Search first: UniProt, PDB (Protein Data Bank), InterPro, Pfam, AlphaFold

  • Metabolic Changes: Alterations in metabolic processes (energy metabolism, lipid metabolism, amino acid metabolism)

    Search first: KEGG, BioCyc, HMDB (Human Metabolome Database), BRENDA

  • Immune System Involvement: Role of immune response (autoimmunity, immunodeficiency, chronic inflammation)

    Search first: ImmPort, Immunome Database, IEDB, Gene Ontology

  • Tissue Damage Mechanisms: How tissues/ are injured (oxidative stress, ischemia, fibrosis, necrosis)

    Search first: PubMed, Gene Ontology, Reactome

  • Biochemical Abnormalities: Specific molecular defects (enzyme deficiencies, receptor dysfunction, ion channel defects)

    Search first: BRENDA, UniProt, KEGG, OMIM, PubMed

  • Epigenetic Changes: DNA methylation, histone modifications affecting gene expression in disease

    Search first: ENCODE, Roadmap Epigenomics, MethBase, DiseaseMeth

  • Molecular Profiling (if available):
  • Transcriptomics/gene expression changes > Search first: GEO (Gene Expression Omnibus), ArrayExpress, GTEx, Human Cell Atlas, SRA
  • Proteomics findings > Search first: PRIDE, ProteomeXchange, Human Protein Atlas, STRING, BioGRID
  • Metabolomics signatures > Search first: MetaboLights, Metabolomics Workbench, HMDB, METLIN
  • Lipidomics alterations > Search first: LIPID MAPS, SwissLipids, LipidHome, Metabolomics Workbench
  • Genomic structural features > Search first: UCSC Genome Browser, Ensembl, NCBI, dbVar, DGV
  • Advanced Technologies (if applicable):
  • Single-cell analysis findings (cell-type specific mechanisms, cellular heterogeneity) > Search first: Human Cell Atlas, Single Cell Portal, GEO, CELLxGENE
  • Spatial transcriptomics findings > Search first: GEO, Spatial Research, Vizgen, 10x Genomics data
  • Multi-omics integration results > Search first: TCGA, ICGC, cBioPortal, LinkedOmics, PubMed
  • Functional genomics screens (CRISPR, RNAi) > Search first: DepMap, GenomeRNAi, PubMed, BioGRID ORCS

For each mechanism, describe: - The causal chain from initial trigger to clinical manifestation - Which mechanisms are upstream vs downstream - What cell types and biological processes are involved - Suggest GO terms for biological processes and CL terms for cell types

7. Anatomical Structures Affected

  • Organ Level:
  • Primary organs directly affected
  • Secondary organ involvement (complications, secondary effects)
  • Body systems involved (cardiovascular, nervous, digestive, respiratory, endocrine, etc.)

    Search first: Uberon, FMA (Foundational Model of Anatomy), OMIM, HPO, ICD-11, MeSH, SNOMED CT

  • Tissue and Cell Level:
  • Specific tissue types affected (epithelial, connective, muscle, nervous)
  • Specific cell populations targeted (with Cell Ontology terms)

    Search first: Uberon, Human Protein Atlas, Cell Ontology, Human Cell Atlas, CellMarker, PanglaoDB

  • Subcellular Level:
  • Cellular compartments involved (mitochondria, nucleus, ER, lysosomes) (with GO Cellular Component terms)

    Search first: Gene Ontology (Cellular Component), UniProt, Human Protein Atlas

  • Localization:
  • Specific anatomical sites (with UBERON terms) > Search first: FMA, Uberon, NeuroNames (for brain), SNOMED CT
  • Lateralization (unilateral, bilateral, asymmetric) > Search first: HPO, clinical literature, imaging databases

8. Temporal Development

  • Onset:
  • Typical age of onset (congenital, pediatric, adult, geriatric)
  • Onset pattern (acute, subacute, chronic, insidious)

    Search first: OMIM, Orphanet, HPO, PubMed

  • Progression:
  • Disease stages (early, intermediate, advanced, end-stage) > Search first: Cancer Staging Manual (AJCC), WHO classifications, PubMed
  • Progression rate (rapid, slow, variable)
  • Disease course pattern (episodic, relapsing-remitting, progressive, stable)
  • Disease duration (self-limited, chronic lifelong)

    Search first: Disease registries, longitudinal cohort databases, natural history studies, PubMed, Orphanet, OMIM

  • Patterns:
  • Remission patterns (spontaneous, treatment-induced) > Search first: Clinical trial databases, disease registries, PubMed
  • Critical periods (time windows of vulnerability or opportunity for intervention) > Search first: PubMed, developmental biology databases, clinical guidelines

9. Inheritance and Population

  • Epidemiology:
  • Prevalence (cases per 100,000 at given time)
  • Incidence (new cases per 100,000 per year)

    Search first: Orphanet, CDC, WHO, GBD (Global Burden of Disease), national registries, SEER, disease registries

  • For Genetic Etiology:
  • Inheritance pattern (AD, AR, X-linked, mitochondrial, multifactorial, polygenic) > Search first: OMIM, Orphanet, ClinVar, GTR (Genetic Testing Registry)
  • Penetrance (complete, incomplete, age-dependent) > Search first: ClinVar, OMIM, PubMed, ClinGen
  • Expressivity (variable, consistent) > Search first: OMIM, ClinVar, PubMed
  • Genetic anticipation (increasing severity in successive generations) > Search first: OMIM, PubMed (especially for repeat expansion disorders)
  • Germline mosaicism > Search first: ClinVar, OMIM, genetic counseling literature, PubMed
  • Founder effects (population-specific mutations) > Search first: gnomAD, population genetics databases, PubMed
  • Consanguinity role > Search first: OMIM, population studies, genetic counseling resources
  • Carrier frequency > Search first: gnomAD, carrier screening databases, GeneReviews, GTR
  • Population Demographics:
  • Affected populations (ethnic or demographic groups with higher prevalence) > Search first: gnomAD, 1000 Genomes, PAGE Study, PubMed, population registries
  • Geographic distribution (endemic areas, regional variation) > Search first: WHO, CDC, GBD, Orphanet, geographic epidemiology databases
  • Geographic distribution of specific variants
  • Sex ratio (male:female) > Search first: Disease registries, OMIM, PubMed, epidemiological databases
  • Age distribution of affected individuals > Search first: CDC, disease registries, SEER, Orphanet

10. Diagnostics

  • Clinical Tests:
  • Laboratory tests (blood, urine, tissue chemistry, specific enzyme assays) > Search first: LOINC, LabTests Online, PubMed
  • Biomarkers (proteins, metabolites, genetic markers, circulating biomarkers) > Search first: FDA Biomarker List, BEST (Biomarkers, EndpointS, and other Tools), PubMed
  • Imaging studies (X-ray, CT, MRI, PET, ultrasound) > Search first: RadLex, DICOM, Radiopaedia, imaging databases
  • Functional tests (pulmonary function, cardiac stress tests) > Search first: LOINC, clinical guidelines, PubMed
  • Electrophysiology (EEG, EMG, ECG, nerve conduction studies) > Search first: LOINC, clinical neurophysiology databases, PubMed
  • Biopsy findings (histopathology, immunohistochemistry) > Search first: SNOMED CT, College of American Pathologists resources, PubMed
  • Pathology findings (microscopic examination) > Search first: SNOMED CT, Digital Pathology databases, PubMed
  • Genetic Testing:

    Search first: GTR (Genetic Testing Registry), GeneReviews, ClinGen

  • Overview of recommended genetic testing approach
  • Whole genome sequencing (WGS) utility > Search first: GTR, ClinVar, GEL (Genomics England), gnomAD
  • Whole exome sequencing (WES) utility > Search first: GTR, ClinVar, OMIM, GeneMatcher
  • Gene panels (which panels, which genes) > Search first: GTR, ClinVar, laboratory-specific databases
  • Single gene testing > Search first: GTR, ClinVar, OMIM, GeneReviews
  • Chromosomal microarray (CMA) > Search first: DECIPHER, ClinVar, dbVar, ECARUCA
  • Karyotyping > Search first: Chromosome Abnormality Database, ClinVar, cytogenetics resources
  • FISH > Search first: ClinVar, cytogenetics databases, PubMed
  • Mitochondrial DNA testing > Search first: MITOMAP, MSeqDR, ClinVar, GTR
  • Repeat expansion testing > Search first: GTR, ClinVar, repeat expansion databases, PubMed
  • Omics-Based Diagnostics (if applicable):
  • RNA sequencing / transcriptomics > Search first: GEO, ArrayExpress, GTEx, RNA-seq databases
  • Proteomics > Search first: PRIDE, ProteomeXchange, FDA Biomarker database
  • Metabolomics > Search first: MetaboLights, Metabolomics Workbench, HMDB
  • Epigenomics > Search first: GEO, ENCODE, Roadmap Epigenomics, MethBase
  • Liquid biopsy > Search first: COSMIC, ClinVar, liquid biopsy databases, PubMed
  • Clinical Criteria:
  • Standardized diagnostic criteria (DSM, ICD, society guidelines) > Search first: DSM-5, ICD-11, clinical society guidelines, UpToDate
  • Differential diagnosis (other conditions to rule out, with distinguishing features) > Search first: DynaMed, UpToDate, clinical decision support systems
  • Screening:
  • Screening methods for asymptomatic individuals (newborn screening, carrier screening, cascade screening) > Search first: ACMG recommendations, CDC newborn screening, GTR

11. Outcome/Prognosis

  • Survival and Mortality:
  • Survival rate (5-year, 10-year, overall) > Search first: SEER, cancer registries, disease-specific registries, PubMed
  • Life expectancy (with and without treatment if applicable) > Search first: Orphanet, disease registries, actuarial databases, PubMed
  • Mortality rate > Search first: CDC, WHO, GBD, national mortality databases
  • Disease-specific mortality (deaths directly attributable to disease) > Search first: Disease registries, CDC Wonder, GBD, PubMed
  • Morbidity and Function:
  • Morbidity (disease-related disability and health impacts) > Search first: GBD, WHO, disability databases, PubMed
  • Disability outcomes (long-term functional impairments) > Search first: ICF (International Classification of Functioning), disability registries
  • Quality of life measures (EQ-5D, SF-36, PROMIS, disease-specific tools) > Search first: EQ-5D database, SF-36, PROMIS, PubMed
  • Disease Course:
  • Complications (secondary problems: infections, organ failure, etc.) > Search first: ICD codes, disease registries, clinical databases, PubMed
  • Recovery potential (likelihood and extent of recovery, with vs without treatment) > Search first: Natural history studies, rehabilitation databases, PubMed
  • Prediction:
  • Prognostic factors (age, disease severity, biomarkers, treatment response) > Search first: Prognostic models databases, clinical calculators, PubMed
  • Prognostic biomarkers (molecular markers predicting disease course) > Search first: FDA Biomarker database, PubMed, cancer prognostic databases

12. Treatment

  • Pharmacotherapy:
  • Pharmacological treatments (drug names, drug classes, mechanisms of action) > Search first: DrugBank, RxNorm, ATC classification, DailyMed, FDA databases
  • Pharmacogenomics (how genetic variants affect drug metabolism, efficacy, toxicity) > Search first: PharmGKB, CPIC (Clinical Pharmacogenetics), FDA Table of PGx Biomarkers
  • Advanced Therapeutics:
  • Gene therapy (viral vectors, CRISPR, gene replacement, gene editing) > Search first: ClinicalTrials.gov, FDA gene therapy database, ASGCT resources
  • Cell therapy (stem cell transplant, CAR-T, cellular therapeutics) > Search first: ClinicalTrials.gov, FDA cell therapy database, FACT standards
  • RNA-based therapies (ASOs, siRNA, mRNA therapies) > Search first: ClinicalTrials.gov, FDA approvals, PubMed
  • Targeted therapies (treatments directed at specific molecular targets) > Search first: My Cancer Genome, OncoKB, ClinicalTrials.gov, FDA approvals
  • Immunotherapies (checkpoint inhibitors, monoclonal antibodies) > Search first: Cancer Immunotherapy Database, FDA approvals, ClinicalTrials.gov
  • Surgical and Interventional:
  • Surgical interventions (types of surgery, timing, outcomes) > Search first: CPT codes, surgical registries, clinical guidelines, PubMed
  • Supportive and Rehabilitative:
  • Supportive care (symptom management, pain control, nutrition) > Search first: Clinical guidelines, Cochrane Library, PubMed
  • Rehabilitation (physical therapy, occupational therapy, speech therapy) > Search first: Rehabilitation medicine databases, clinical guidelines, PubMed
  • Experimental:
  • Experimental treatments in clinical trials (with NCT identifiers if available) > Search first: ClinicalTrials.gov, EU Clinical Trials Register, WHO ICTRP
  • Treatment Outcomes:
  • Treatment response rates > Search first: Clinical trial databases, FDA reviews, systematic reviews, PubMed
  • Side effects and adverse events > Search first: FDA Adverse Event Reporting System (FAERS), MedWatch, PubMed
  • Treatment Strategy:
  • Treatment algorithms (clinical pathways, decision trees) > Search first: Clinical practice guidelines, NCCN Guidelines, UpToDate
  • Combination therapies > Search first: ClinicalTrials.gov, treatment guidelines, PubMed
  • Personalized medicine approaches (genotype-guided treatment) > Search first: My Cancer Genome, CIViC, PharmGKB, precision medicine databases

For each treatment, suggest NCIT (NCI Thesaurus) clinical-intervention terms where applicable.

13. Prevention

  • Prevention Levels:
  • Primary prevention (preventing disease occurrence: vaccination, risk factor modification) > Search first: CDC, WHO, USPSTF recommendations, Cochrane Library
  • Secondary prevention (early detection and treatment: screening programs, early intervention) > Search first: USPSTF, CDC screening guidelines, WHO
  • Tertiary prevention (preventing complications in those with disease) > Search first: Clinical guidelines, disease management protocols, PubMed
  • Immunization: Vaccine strategies (if applicable)

    Search first: CDC vaccine schedules, WHO immunization, FDA vaccine database

  • Screening and Early Detection:
  • Screening programs (population-based: newborn screening, cancer screening) > Search first: CDC screening programs, USPSTF, cancer screening databases
  • Genetic screening (carrier screening, preimplantation genetic diagnosis, prenatal testing) > Search first: ACMG recommendations, ACOG guidelines, GTR
  • Risk stratification (identifying high-risk individuals for targeted prevention) > Search first: Risk prediction models, clinical calculators, PubMed
  • Behavioral Interventions: Lifestyle modifications to reduce risk

    Search first: CDC, WHO, behavioral intervention databases, Cochrane Library

  • Counseling: Genetic counseling (risk assessment, family planning guidance)

    Search first: NSGC resources, ACMG guidelines, GeneReviews

  • Public Health:
  • Public health interventions (sanitation, vector control, health education) > Search first: CDC, WHO, public health databases, PubMed
  • Environmental interventions (reducing environmental risk factors) > Search first: EPA databases, WHO environmental health, PubMed
  • Prophylaxis: Preventive medications or procedures

    Search first: Clinical guidelines, FDA approvals, PubMed

14. Other Species / Natural Disease

  • Taxonomy: Species affected (with NCBI Taxon identifiers)

    Search first: NCBI Taxonomy

  • Breed: Specific breeds affected (with VBO identifiers if applicable)

    Search first: VBO (Vertebrate Breed Ontology)

  • Gene: Orthologous genes in other species (with NCBI Gene IDs)

    Search first: NCBI Gene

  • Natural Disease:
  • Naturally occurring disease in other species (companion animals, wildlife) > Search first: OMIA (Online Mendelian Inheritance in Animals), VetCompass, PubMed
  • Veterinary relevance and importance in animal health > Search first: OMIA, veterinary databases, PubMed
  • Comparative Biology:
  • Comparative pathology (similarities and differences across species) > Search first: OMIA, comparative pathology databases, PubMed
  • Evolutionary conservation of disease mechanisms > Search first: HomoloGene, OrthoMCL, Alliance of Genome Resources
  • Transmission (if applicable):
  • Zoonotic potential > Search first: CDC zoonotic diseases, WHO zoonoses, GIDEON
  • Cross-species susceptibility > Search first: NCBI Taxonomy, veterinary databases, PubMed

15. Model Organisms

  • Model Types:
  • Model organism type (mammalian, invertebrate, cellular, in vitro) > Search first: Alliance of Genome Resources, model organism databases
  • Specific model systems (mouse, rat, zebrafish, Drosophila, C. elegans, yeast, cell lines, organoids, iPSCs) > Search first: MGI, RGD, ZFIN, FlyBase, WormBase, SGD, ATCC, Cellosaurus
  • Induced models (drug treatment, surgical intervention, environmental manipulation) > Search first: MGI, model organism databases, PubMed
  • Genetic Models:
  • Types available (knockout, knock-in, transgenic, conditional, humanized) > Search first: MGI, IMPC, KOMP, EuMMCR, IMSR
  • Model Characteristics:
  • Phenotype recapitulation (how well model reproduces human disease features) > Search first: Model organism databases, comparative studies, PubMed
  • Model limitations (aspects of human disease not captured) > Search first: Model organism databases, PubMed, review articles
  • Applications:
  • Research applications (what aspects of disease can be studied) > Search first: Model organism databases, PubMed
  • Resources:
  • Model databases > Search first: MGI, RGD, ZFIN, FlyBase, WormBase, IMSR, EMMA, MMRRC

Citation Requirements

  • Cite primary literature (PMID preferred) for all mechanistic and clinical claims
  • Prioritize recent reviews and landmark papers
  • Include direct quotes from abstracts where possible to support key statements
  • Distinguish evidence source types: human clinical, model organism, in vitro, computational

Output Format

Structure your response as a comprehensive narrative organized by the sections above. For each section, provide: - Factual content with specific details (numbers, percentages, gene names, variant nomenclature) - Ontology term suggestions (HPO, GO, CL, UBERON, CHEBI, NCIT, MONDO) where applicable - Evidence citations with PMIDs - Direct quotes from abstracts to support key claims - Clear indication when information is not available or not applicable for this disease

This report will be used to populate a disease knowledge base entry with: - Pathophysiology descriptions with causal chains - Gene/protein annotations (HGNC, GO terms) - Phenotype associations (HP terms) with frequencies - Cell type involvement (CL terms) - Anatomical locations (UBERON terms) - Chemical entities (CHEBI terms) - Treatment annotations (NCIT terms) - Evidence items with PMIDs and exact abstract quotes - Epidemiology, prognosis, diagnostic, and prevention information - Animal model descriptions with phenotype recapitulation details

Alopecia–Intellectual Disability Syndrome 1 (APMR1): comprehensive disease-characteristics report

Executive summary and evidence limits

Alopecia–intellectual disability syndrome 1 (APMR1; historically alopecia–mental retardation syndrome 1) is an exceptionally rare autosomal-recessive neurocutaneous disorder characterized principally by partial or complete alopecia and intellectual disability. The molecular evidence currently rests mainly on one large consanguineous Iranian family: seven affected relatives were homozygous for AHSG c.950G>A (p.Arg317His; rs201849460), whereas seven unaffected relatives carried either one variant allele or the reference genotype. The association is compelling but not yet supported by numerous unrelated families or a disease-recapitulating experimental model. Accordingly, AHSG should be treated as the reported/proposed APMR1 causal gene, with limited replication, rather than as a comprehensively validated gene–disease relationship. (sailani2017associationofahsg pages 4-7, sailani2017associationofahsg pages 1-3, sailani2017associationofahsg pages 3-4)

The most important recent disease-family update is a 2024 comparative APMR study. It continues to distinguish APMR1 from LSS-related APMR4 and describes APMR1 as generally involving mild-to-moderate intellectual disability; however, it adds little new APMR1-specific molecular evidence. (kang2024clinicalandgenetic pages 1-2)

Domain Key findings Quantitative details Evidence level Citation
Identity / identifier Disease resolved as alopecia-mental retardation syndrome 1 (APMR1), a very rare autosomal recessive condition mapped to chromosome 3q26.33-q27.3; characterized by alopecia with intellectual disability. OMIM given as 203650. Single disease entity discussed in one primary molecular report; linkage region reported as 17 Mb on chr3. Human clinical / gene-mapping (sailani2017associationofahsg pages 1-3, sailani2017associationofahsg pages 4-7)
Gene and variant Candidate causal gene is AHSG (alpha-2-HS-glycoprotein; fetuin-A; OMIM 138680). Reported disease-associated variant: c.950G>A (p.Arg317His) in exon 7; dbSNP rs201849460. Variant genomic position reported as chr3:186338565; rarity in ExAC reported as MAF 0.0008%. In silico scores: MutationTaster 0.95, PolyPhen 0.99, SIFT 0.0. Human segregation + computational (sailani2017associationofahsg pages 1-3, sailani2017associationofahsg pages 3-4)
Inheritance / family Inheritance is consistent with autosomal recessive transmission in a large consanguineous Iranian family. Variant segregated with disease. 7 affected homozygous individuals; 7 unaffected relatives were heterozygous or homozygous reference; segregation significance reported as chi-square P=0.01. Human segregation (sailani2017associationofahsg pages 1-3, sailani2017associationofahsg pages 4-7, sailani2017associationofahsg pages 3-4)
Phenotype and patient counts Core phenotype is alopecia plus intellectual disability. Hair loss may be complete or partial. APMR1 is described in 2024 context as having mild-to-moderate ID; developmental delay and epilepsy have been noted in APMR1 generally, but were not individually detailed in the extracted 2017 family table. 7 affected relatives total; ages explicitly visible for 7 individuals: 3Y, 4Y, 14Y, 17Y, 21Y, 23Y, 24Y; sexes: 4 male, 3 female; alopecia pattern among listed individuals: 3 complete, 4 partial; IQ range 40-54. Human clinical observation (sailani2017associationofahsg pages 3-4, kang2024clinicalandgenetic pages 1-2)
Functional evidence AHSG/fetuin-A is implicated in protein processing/post-translational modification, BMP/TGF-beta antagonism, keratinocyte migration, and possible brain developmental roles. The APMR1 variant lies in the protein processing region and is predicted to disrupt a phosphorylation motif near Thr319; patient serum AHSG showed altered migration on SDS-PAGE. Predicted loss/change of kinase recognition around p.Thr319 with probabilities reported in one analysis as 0.96-0.74 for PKA/DMPK/AUR kinases; western blot showed two bands in affected versus single bands in unaffected controls. In vitro / biochemical + computational (sailani2017associationofahsg pages 4-7, sailani2017associationofahsg pages 3-4, sailani2017associationofahsg pages 7-8, sailani2017associationofahsg pages 8-9)
Diagnosis No disease-specific standardized diagnostic criteria were identified. Current practical diagnosis depends on recognizing the phenotype and confirming biallelic AHSG variation, typically via whole-exome sequencing or other molecular testing. Broader ichthyosis/alopecia-neurodevelopmental literature supports NGS for rare syndromic differential diagnosis. In a syndromic/non-syndromic ichthyosis cohort, NGS achieved a molecular diagnosis in 53/64 patients (82.8%), illustrating utility of panel/WES approaches for overlapping phenotypes. Human diagnostic practice / extrapolated rare-disease genomics (sailani2017associationofahsg pages 1-3, kang2024clinicalandgenetic pages 1-2)
Treatment / trials No disease-specific therapy or management guideline for APMR1 was found in the retrieved evidence. Management is therefore presumed supportive and multidisciplinary (developmental, neurologic, dermatologic, rehabilitation, genetic counseling) rather than disease-modifying. No relevant interventional clinical trials were retrieved. 0 relevant trials found in the searched trial results. Evidence gap / no active trial evidence retrieved (sailani2017associationofahsg pages 3-4)
Major evidence gaps Evidence base is extremely limited: one genetically resolved family, sparse natural-history data, no prevalence/incidence estimates, no penetrance estimates, no standardized diagnostic criteria, no biomarker validation, no disease-specific therapy, and no direct APMR1 animal model identified. Existing animal evidence for AHSG is indirect and comes from other phenotypes involving fetuin-A deficiency. Human molecular evidence currently rests mainly on 1 family / 7 affected individuals; indirect AHSG biology from knockout animals links fetuin-A deficiency to mineralization and bone phenotypes rather than a fully recapitulated APMR1 syndrome. Animal indirect + evidence gap (sailani2017associationofahsg pages 1-3, merdlerrabinowicz2019fetuinadeficiencyis pages 3-4, merdlerrabinowicz2019fetuinadeficiencyis pages 4-5)

Table: This table summarizes the strongest currently available evidence for alopecia-mental retardation syndrome 1 (APMR1), including identifiers, AHSG variant data, family segregation, phenotype counts, functional findings, and the major unresolved gaps. It is useful for rapidly distinguishing established human evidence from indirect mechanistic or animal evidence.

1. Disease information

Definition and identifiers

  • Preferred name: Alopecia–intellectual disability syndrome 1.
  • Historical names/synonyms: alopecia–mental retardation syndrome 1; APMR1; alopecia with mental retardation syndrome; AHSG-associated alopecia–intellectual disability syndrome.
  • OMIM phenotype: 203650.
  • Mapped locus: chromosome 3q26.33–q27.3, originally a roughly 17-Mb linkage interval.
  • Gene entry: AHSG, OMIM 138680; protein alpha-2-HS-glycoprotein/fetuin-A.
  • MONDO, Orphanet, MeSH, ICD-10 and ICD-11: a disease-specific identifier/code was not established in the retrieved evidence. For coding, a combination of alopecia, intellectual disability, and genetic-syndrome categories may be necessary; these are not equivalent to a dedicated APMR1 code and should not be entered as exact mappings.
  • Category: Mendelian, autosomal recessive, neurocutaneous/neuroectodermal syndrome. (sailani2017associationofahsg pages 1-3)

The evidence is aggregated family-level research data, not EHR-derived population data. Individual-level details were reported for seven affected relatives, but no registry or population cohort exists in the retrieved literature. (sailani2017associationofahsg pages 3-4)

Primary source: Sailani et al., Human Genetics, published January 2017, DOI 10.1007/s00439-016-1756-5. A PMID was not available in the retrieved record and should be verified directly in PubMed before database deposition. (sailani2017associationofahsg pages 1-3)

2. Etiology

Causal and genetic factors

The reported molecular cause is homozygosity for AHSG c.950G>A, p.Arg317His, an exon-7 missense variant. It lay both within the prior linkage interval and a run of homozygosity, segregated with disease, and was extremely rare in ExAC (MAF 0.0008%). Reported predictions were MutationTaster 0.95, PolyPhen 0.99, and SIFT 0.0. The variant affects a conserved residue in a protein-processing region. (sailani2017associationofahsg pages 4-7, sailani2017associationofahsg pages 1-3)

The variant was homozygous in all seven affected relatives. Seven unaffected relatives were heterozygous or reference homozygotes; reported segregation was χ² P=0.01. This supports recessive inheritance, but one pedigree cannot establish population-wide penetrance or the full allelic spectrum. (sailani2017associationofahsg pages 4-7, sailani2017associationofahsg pages 3-4)

Other risk, protective, and gene–environment factors

  • Established risk: biallelic inheritance of the familial AHSG allele; parental consanguinity increases the probability that descendants inherit the same rare allele from both parents.
  • Environmental or infectious risk factors: none demonstrated.
  • Lifestyle risks: none demonstrated.
  • Protective alleles, modifier genes, or protective exposures: none reported.
  • Gene–environment interaction: not studied.
  • Somatic contribution: unsupported; this is presumed a germline disorder.

These absences reflect lack of evidence, not proof that modifiers cannot exist.

3. Phenotypes

Core observed phenotype

All seven molecularly described relatives had alopecia and intellectual disability. Ages were 3, 4, 14, 17, 21, 23, and 24 years; there were four males and three females. Three were described as having complete alopecia and four partial alopecia. All had reported Stanford–Binet IQ values in the 40–54 range. Thus, within this selected family, both major manifestations occurred in 7/7 (100%), although this cannot be generalized to all future AHSG genotypes. (sailani2017associationofahsg pages 7-8, sailani2017associationofahsg pages 3-4)

The disease-level description includes loss of scalp hair and absence of eyebrows and eyelashes. Recent comparative literature classifies APMR1 intellectual disability as usually mild-to-moderate and states that developmental delay and epilepsy can occur in APMR1, but the retrieved primary family text did not provide patient-by-patient seizure histories, onset ages, EEG results, or developmental milestones. (sailani2017associationofahsg pages 1-3, kang2024clinicalandgenetic pages 1-2)

Ontology-ready phenotype suggestions

Manifestation Type/course Suggested HPO annotation
Partial or complete scalp alopecia Physical sign; pediatric presentation documented; persistence likely, but formal longitudinal data absent Alopecia (HP:0001596); consider partial/total alopecia child terms after HPO verification
Absent/sparse eyebrows Physical sign; disease-level description Sparse eyebrow (HP:0045075) or absent eyebrow term after ontology verification
Absent/sparse eyelashes Physical sign Sparse eyelashes (HP:0000653) or absent eyelashes term after verification
Intellectual disability, IQ 40–54 Neurodevelopmental/behavioral phenotype; mild-to-moderate in recent comparison Intellectual disability (HP:0001249); moderate ID HP:0002342 where supported individually
Developmental delay Reported at syndrome-comparison level, not quantified in the foundational family Global developmental delay (HP:0001263)
Epilepsy/seizures Reported as possible in APMR1 comparison; individual frequencies unavailable Seizure (HP:0001250) / Epilepsy (HP:0001250 family of terms)

Quality of life

No EQ-5D, SF-36, PROMIS, caregiver-burden, educational-attainment, or adaptive-function data exist in the retrieved literature. Intellectual disability is expected to affect learning and independent function; alopecia may affect appearance and psychosocial well-being, but APMR1-specific quantitative effects have not been measured.

4. Genetic and molecular information

Gene and variant annotation

  • Gene: AHSG (alpha-2-HS-glycoprotein), encoding secreted fetuin-A.
  • Variant: c.950G>A (p.Arg317His); exon 7; rs201849460; reported genomic coordinate chr3:186338565 in the source assembly.
  • Variant class: missense, germline, homozygous in affected relatives.
  • Population frequency: ExAC MAF 0.0008% in the 2017 report; current gnomAD frequency and ancestry-specific counts require direct contemporary database verification.
  • ClinVar/ACMG status: no current ClinVar assertion was established from retrieved evidence. “Pathogenic” should not be imported solely from prediction scores; a contemporary ACMG/AMP assessment should incorporate segregation, rarity, phenotype specificity, functional data, and any newer submissions.
  • Functional direction: probably altered protein maturation/post-translational regulation rather than complete null function. The exact mechanism—loss of function, hypomorph, neomorph, or altered phosphorylation—remains unresolved. (sailani2017associationofahsg pages 4-7, sailani2017associationofahsg pages 1-3, sailani2017associationofahsg pages 3-4)

No APMR1-associated copy-number variant, translocation, repeat expansion, mitochondrial variant, modifier gene, methylation signature, or other epigenetic abnormality has been reported.

5. Environmental information

No toxins, radiation, pollution, occupation, diet, smoking, alcohol, physical activity, medication, or infectious agent has been causally associated with APMR1. Because the disorder segregates as a rare Mendelian trait, environmental exposure is not considered the primary cause. Environmental influences on hair retention, seizures, cognition, or AHSG biology have not been tested specifically in affected people.

6. Mechanism and pathophysiology

Normal protein biology

Fetuin-A is an approximately 52-kDa, negatively charged, secreted glycoprotein produced principally by hepatocytes. It is also produced by osteocytes and, to a lesser extent, osteoblasts. It binds calcium phosphate, forms soluble protein–mineral complexes, and inhibits ectopic calcification. Fetuin-A can mimic a TGF-β type-II receptor and antagonize TGF-β/BMP-family ligands, with reported binding to TGF-β1/2 and BMP-2, BMP-4, and BMP-6. (merdlerrabinowicz2019fetuinadeficiencyis pages 3-4, merdlerrabinowicz2019fetuinadeficiencyis pages 5-5)

Relevant to APMR1, AHSG is strongly expressed during development: the protein has high fetal plasma and CSF concentrations, is synthesized by early developing neurons in immature neocortex, and is expressed in developing hair follicles where basal keratinocytes reorganize into follicular placodes. The 2017 work also reported promotion of primary keratinocyte migration and greater expression in fetal than postnatal skin. These observations provide biological plausibility for combined hair and neurodevelopmental phenotypes. (sailani2017associationofahsg pages 7-8, sailani2017associationofahsg pages 8-9)

Proposed causal chain

  1. Upstream genetic event: homozygous AHSG p.Arg317His.
  2. Molecular consequence: disruption of a recognition motif near Thr319; computational analyses predicted altered PKA/DMPK/AUR-family kinase recognition, with reported probabilities around 0.74–0.96.
  3. Protein consequence: altered maturation or post-translational modification. Patient-serum Western blot showed two AHSG bands in affected people versus a single band in unaffected controls.
  4. Cellular/tissue consequences, still hypothetical: disturbed fetuin-A signaling or extracellular availability may impair keratinocyte migration/hair-follicle placode development and alter developmental BMP/TGF-β regulation in the immature neocortex.
  5. Clinical outcome: alopecia plus intellectual/developmental impairment, with possible epilepsy. (sailani2017associationofahsg pages 4-7, sailani2017associationofahsg pages 3-4)

Steps 1 and segregation are human genetic observations; step 3 is human biochemical evidence; the links from altered bands/phosphorylation to follicular and neural dysfunction remain mechanistic hypotheses rather than demonstrated causal experiments.

Suggested ontology annotations

  • GO biological processes: protein phosphorylation (GO:0006468), protein processing (GO:0016485), BMP signaling pathway (GO:0030509), TGF-β receptor signaling (GO:0007179), keratinocyte migration, hair-follicle development (GO:0001942), nervous-system development (GO:0007399), biomineralization (GO:0110148).
  • GO cellular components: extracellular region (GO:0005576), extracellular space (GO:0005615), blood microparticle/serum-associated compartment where appropriate.
  • Cell Ontology candidates: hepatocyte (CL:0000182), keratinocyte (CL:0000312), neuron (CL:0000540), osteocyte (CL:0000137), osteoblast (CL:0000062). Hair-follicle placode/basal keratinocyte terms should be checked against the current CL release.

Immune, metabolic, and omics evidence

There is no demonstrated autoimmune alopecia, immunodeficiency, chronic inflammation, specific metabolomic signature, lipidomic profile, transcriptomic signature, proteomic panel, single-cell dataset, spatial-transcriptomic study, multi-omics integration, or CRISPR/RNAi screen for APMR1. Fetuin-A’s mineral metabolism functions are established generally, but no mineral or skeletal abnormality was quantified in the APMR1 family.

7. Anatomical structures affected

The directly observed organ systems are:

  • Integumentary: scalp hair follicles; eyebrows and eyelashes. Suggested UBERON terms include hair follicle (UBERON:0002073), scalp, eyebrow, and eyelash structures after current-release verification.
  • Nervous system: developmental brain/cognitive function; the neocortex is biologically plausible from fetal AHSG localization, but no APMR1-specific neuropathology or imaging lesion was established. Suggested terms: brain (UBERON:0000955) and cerebral cortex (UBERON:0000956).
  • Cell/tissue: follicular keratinocytes and developing neurons are candidate affected populations.
  • Subcellular level: the evidence points to a secreted extracellular protein and altered post-translational processing; no disease-specific organelle lesion is known. (sailani2017associationofahsg pages 7-8, sailani2017associationofahsg pages 8-9)

Alopecia is not described as unilateral; involvement appears generalized/bilateral. Formal lateralization data are absent.

8. Temporal development

Affected children were documented as young as age 3, supporting early childhood expression. The disease is frequently described within the broader APMR family as congenital or early-onset alopecia, but exact onset dates were not available for the APMR1 relatives. Intellectual impairment is developmental rather than an adult neurodegenerative presentation. (sailani2017associationofahsg pages 3-4)

No validated disease stages, progression rate, remission pattern, critical therapeutic window, or longitudinal natural-history series exists. Persistence into ages 21–24 indicates a chronic/lifelong phenotype, but whether partial alopecia predictably progresses to complete alopecia is unproven.

9. Inheritance and population

  • Inheritance: autosomal recessive.
  • Pedigree: consanguineous Iranian family.
  • Observed sex distribution: 4 male and 3 female affected relatives, consistent with an autosomal condition but too small for a meaningful sex ratio.
  • Penetrance: appeared complete among seven homozygotes in this family; population-level penetrance is unknown.
  • Expressivity: variable alopecia severity—3/7 complete and 4/7 partial—despite the same familial genotype.
  • Anticipation: not reported and not mechanistically expected for a missense allele.
  • Germline mosaicism: not reported.
  • Founder effect: not established beyond one consanguineous kindred.
  • Carrier frequency: unknown.
  • Prevalence/incidence: no reliable cases-per-100,000 estimate. The evidence base of one molecularly resolved family implies an ultra-rare disorder but does not permit a numerical prevalence calculation. (sailani2017associationofahsg pages 1-3, sailani2017associationofahsg pages 3-4)

10. Diagnostics

Recommended practical workflow

  1. Clinical assessment: document distribution and onset of scalp/eyebrow/eyelash alopecia; complete dermatologic and hair-shaft examination; developmental, neurologic, seizure, hearing, vision, growth, and dysmorphology assessment.
  2. Phenotyping: standardized cognitive/developmental testing and three-generation pedigree, including consanguinity.
  3. Genomic testing: a neurodevelopmental-disorder/alopecia panel that includes AHSG, or preferably trio/parent–child WES because of extensive differential diagnosis. Confirm candidate variants by Sanger sequencing and segregation analysis.
  4. If sequencing is negative: CNV-aware exome analysis or genome sequencing; CMA is appropriate when syndromic intellectual disability suggests a chromosomal imbalance. Karyotype/FISH are not first-line for this single-nucleotide disorder unless cytogenetic findings are suspected.
  5. Variant interpretation: verify transcript, phase, population frequency in current gnomAD, ClinVar assertions, and phenotype concordance. Functional serum fetuin-A electrophoresis is research-level, not a validated clinical diagnostic assay. (sailani2017associationofahsg pages 1-3, sailani2017associationofahsg pages 3-4)

No validated blood biomarker, enzyme assay, imaging pattern, EEG signature, biopsy criterion, prenatal ultrasound sign, or formal diagnostic score exists.

Differential diagnosis

Important genetic alternatives include APMR2, APMR3, and LSS-related APMR4; IFAP/BRESHECK syndrome; Menkes disease; Woodhouse–Sakati syndrome; Coffin–Siris spectrum; ectodermal dysplasias; and other syndromic alopecias/neurodevelopmental disorders. APMR4 can include congenital alopecia, variable ID, developmental delay, and epilepsy and is caused by biallelic LSS variants. Recent comparison reports mild-to-moderate ID in APMR1/2, severe ID in APMR3, and mild-to-severe ID in APMR4. (kang2024clinicalandgenetic pages 1-2)

Molecular testing is particularly important because phenotype overlap is substantial. In a broader 64-person ichthyosis cohort—not an APMR1 cohort—NGS identified pathogenic variants in 53 patients (82.8%), illustrating the diagnostic value of broad sequencing but not an APMR1-specific sensitivity.

Screening

No population or newborn screening is indicated. Once a familial pathogenic/likely pathogenic genotype is confirmed, targeted cascade carrier testing, prenatal diagnosis, and preimplantation genetic testing are technically feasible. These require genetic counseling and careful acknowledgment that the AHSG–APMR1 relationship has limited independent replication.

11. Outcome and prognosis

No survival curves, mortality rate, life-expectancy estimate, hospitalization rate, or prognostic biomarker has been published. Survival into the mid-20s was documented in the family, and there is no evidence that alopecia itself is life limiting. The principal known morbidity is neurodevelopmental disability, with potential seizure-related morbidity where epilepsy occurs. (sailani2017associationofahsg pages 3-4)

Recovery of established intellectual disability or spontaneous durable hair regrowth has not been documented. No quantitative adaptive-function or quality-of-life outcome is available. Prognostic correlations with alopecia extent, IQ, serum fetuin-A, or genotype are unknown.

12. Treatment and real-world implementation

There is no approved disease-modifying pharmacotherapy, gene therapy, RNA therapy, cell therapy, surgery, or genotype-guided drug regimen for APMR1. No relevant interventional trial was retrieved from ClinicalTrials.gov searches.

Current real-world management is therefore individualized and supportive:

  • early developmental intervention and special education;
  • speech/language, occupational, and physical therapy according to functional need;
  • neurology assessment and standard antiseizure treatment if epilepsy is confirmed;
  • dermatology evaluation, scalp care, cosmetic camouflage, wigs/prostheses, and psychological support;
  • periodic hearing, vision, growth, nutrition, and behavioral assessment based on clinical findings;
  • genetic counseling and family cascade testing.

Suggested NCIt intervention concepts include Genetic Counseling, Occupational Therapy, Physical Therapy, Speech and Language Therapy, Supportive Care, and Anticonvulsant Therapy; exact NCIt codes should be resolved against the current thesaurus. There are no APMR1-specific response rates, adverse-event datasets, pharmacogenomic recommendations, or treatment algorithms.

13. Prevention

The phenotype cannot currently be prevented after an affected genotype is established. Primary prevention is reproductive rather than environmental: carrier identification in the family, informed partner testing, prenatal diagnosis, or preimplantation genetic testing. Secondary prevention consists of early recognition of developmental delay or seizures and prompt intervention. Tertiary prevention includes educational/rehabilitative services, seizure control, psychosocial support, and surveillance tailored to identified complications.

Vaccination, infection prophylaxis, diet, exercise, toxin avoidance, or public-health environmental measures have no disease-specific preventive role beyond standard care.

14. Other species and natural disease

No naturally occurring veterinary counterpart of AHSG-associated APMR1 was identified; no breed association, zoonotic transmission, or cross-species infectious susceptibility applies. AHSG/fetuin-A is evolutionarily conserved, permitting comparative functional study, but conservation alone does not establish an animal disease homolog.

A separate human phenotype—infantile cortical hyperostosis—has been associated with a homozygous AHSG nonsense allele and complete fetuin-A deficiency. This demonstrates allelic/functional relevance of AHSG but should not be merged with APMR1 because its reported phenotype and molecular consequence differ. (merdlerrabinowicz2019fetuinadeficiencyis pages 3-4, merdlerrabinowicz2019fetuinadeficiencyis pages 4-5)

15. Model organisms

Available evidence

Ahsg-null mice are an indirect mechanistic model, not a validated APMR1 model. Reported phenotypes include severe extra-osseous renal calcification, accelerated growth-plate mineralization, increased femoral cortical thickness, a greater than twofold increase in cortical-to-cancellous bone ratio, immature bone islands, growth-plate defects, and shortened proximal limb bones. These findings support fetuin-A’s role in mineral chaperoning and BMP/TGF-β-regulated osteogenesis but do not reproduce the defining human alopecia–intellectual-disability combination. (merdlerrabinowicz2019fetuinadeficiencyis pages 3-4, merdlerrabinowicz2019fetuinadeficiencyis pages 5-5)

No p.Arg317His knock-in mouse, zebrafish, Drosophila, C. elegans, patient-derived iPSC, neural organoid, hair-follicle organoid, or humanized model was identified. The most informative future model would be a homozygous p.Arg317His knock-in system coupled with fetal cortical-neuron and hair-follicle-placode assays; key readouts should include fetuin-A processing/phosphorylation, secretion, BMP/TGF-β signaling, keratinocyte migration, folliculogenesis, neurodevelopment, cognition, and seizure susceptibility.

Expert assessment and research priorities

The strongest evidence is the internally consistent combination of linkage, homozygosity, rarity, segregation in 14 relatives, evolutionary conservation, and altered patient-protein electrophoretic behavior. Nevertheless, the absence of unrelated replicated families and direct variant-specific disease models limits certainty. The altered Western-blot migration shows a biochemical effect but does not prove that loss of Thr319 phosphorylation causes alopecia or intellectual disability. (sailani2017associationofahsg pages 4-7, sailani2017associationofahsg pages 3-4)

Priorities are: (1) identify independent biallelic AHSG cases through GeneMatcher/rare-disease genome programs; (2) perform formal ClinGen gene–disease curation; (3) measure secretion, glycosylation, phosphorylation, BMP/TGF-β antagonism, and migration in variant-engineered keratinocytes and neurons; (4) develop knock-in or patient-derived organoid models; and (5) establish prospective natural-history and patient-reported-outcome data.

Source and quotation note

The key primary report is Sailani et al., published January 2017: https://doi.org/10.1007/s00439-016-1756-5. The recent comparative source is Kang et al., published May 2024: https://doi.org/10.3389/fnins.2024.1301865. The indirect fetuin-A-deficiency/model source is Merdler-Rabinowicz et al., published July 2019: https://doi.org/10.1038/s41390-019-0499-0. (sailani2017associationofahsg pages 1-3, kang2024clinicalandgenetic pages 1-2, merdlerrabinowicz2019fetuinadeficiencyis pages 3-4)

A verbatim abstract for the foundational APMR1 article was not present in the retrieved full-text evidence. To avoid fabricating quotations, its findings have been accurately paraphrased rather than placed in quotation marks. The available 2024 abstract describes APMR disorders as involving congenital alopecia and variable intellectual disability, but that article concerns APMR4 and should not be used as direct evidence for AHSG causality. (kang2024clinicalandgenetic pages 1-2)

References

  1. (sailani2017associationofahsg pages 4-7): M. Reza Sailani, Fereshteh Jahanbani, Jafar Nasiri, Mahdiyeh Behnam, Mansoor Salehi, Maryam Sedghi, Majid Hoseinzadeh, Shinichi Takahashi, Amin Zia, Joshua Gruber, Janet Linnea Lynch, Daniel Lam, Juliane Winkelmann, Semira Amirkiai, Baoxu Pang, Shannon Rego, Safoura Mazroui, Jonathan A. Bernstein, and Michael P. Snyder. Association of ahsg with alopecia and mental retardation (apmr) syndrome. Human Genetics, 136:287-296, Jan 2017. URL: https://doi.org/10.1007/s00439-016-1756-5, doi:10.1007/s00439-016-1756-5. This article has 16 citations and is from a peer-reviewed journal.

  2. (sailani2017associationofahsg pages 1-3): M. Reza Sailani, Fereshteh Jahanbani, Jafar Nasiri, Mahdiyeh Behnam, Mansoor Salehi, Maryam Sedghi, Majid Hoseinzadeh, Shinichi Takahashi, Amin Zia, Joshua Gruber, Janet Linnea Lynch, Daniel Lam, Juliane Winkelmann, Semira Amirkiai, Baoxu Pang, Shannon Rego, Safoura Mazroui, Jonathan A. Bernstein, and Michael P. Snyder. Association of ahsg with alopecia and mental retardation (apmr) syndrome. Human Genetics, 136:287-296, Jan 2017. URL: https://doi.org/10.1007/s00439-016-1756-5, doi:10.1007/s00439-016-1756-5. This article has 16 citations and is from a peer-reviewed journal.

  3. (sailani2017associationofahsg pages 3-4): M. Reza Sailani, Fereshteh Jahanbani, Jafar Nasiri, Mahdiyeh Behnam, Mansoor Salehi, Maryam Sedghi, Majid Hoseinzadeh, Shinichi Takahashi, Amin Zia, Joshua Gruber, Janet Linnea Lynch, Daniel Lam, Juliane Winkelmann, Semira Amirkiai, Baoxu Pang, Shannon Rego, Safoura Mazroui, Jonathan A. Bernstein, and Michael P. Snyder. Association of ahsg with alopecia and mental retardation (apmr) syndrome. Human Genetics, 136:287-296, Jan 2017. URL: https://doi.org/10.1007/s00439-016-1756-5, doi:10.1007/s00439-016-1756-5. This article has 16 citations and is from a peer-reviewed journal.

  4. (kang2024clinicalandgenetic pages 1-2): Qingyun Kang, Hui Kang, Jingwen Tang, Miao Wang, Haojiang Jiang, Ze-shu Ning, and Liwen Wu. Clinical and genetic analyses of apmr4 syndrome caused by novel biallelic lss variants. Frontiers in Neuroscience, May 2024. URL: https://doi.org/10.3389/fnins.2024.1301865, doi:10.3389/fnins.2024.1301865. This article has 3 citations and is from a peer-reviewed journal.

  5. (sailani2017associationofahsg pages 7-8): M. Reza Sailani, Fereshteh Jahanbani, Jafar Nasiri, Mahdiyeh Behnam, Mansoor Salehi, Maryam Sedghi, Majid Hoseinzadeh, Shinichi Takahashi, Amin Zia, Joshua Gruber, Janet Linnea Lynch, Daniel Lam, Juliane Winkelmann, Semira Amirkiai, Baoxu Pang, Shannon Rego, Safoura Mazroui, Jonathan A. Bernstein, and Michael P. Snyder. Association of ahsg with alopecia and mental retardation (apmr) syndrome. Human Genetics, 136:287-296, Jan 2017. URL: https://doi.org/10.1007/s00439-016-1756-5, doi:10.1007/s00439-016-1756-5. This article has 16 citations and is from a peer-reviewed journal.

  6. (sailani2017associationofahsg pages 8-9): M. Reza Sailani, Fereshteh Jahanbani, Jafar Nasiri, Mahdiyeh Behnam, Mansoor Salehi, Maryam Sedghi, Majid Hoseinzadeh, Shinichi Takahashi, Amin Zia, Joshua Gruber, Janet Linnea Lynch, Daniel Lam, Juliane Winkelmann, Semira Amirkiai, Baoxu Pang, Shannon Rego, Safoura Mazroui, Jonathan A. Bernstein, and Michael P. Snyder. Association of ahsg with alopecia and mental retardation (apmr) syndrome. Human Genetics, 136:287-296, Jan 2017. URL: https://doi.org/10.1007/s00439-016-1756-5, doi:10.1007/s00439-016-1756-5. This article has 16 citations and is from a peer-reviewed journal.

  7. (merdlerrabinowicz2019fetuinadeficiencyis pages 3-4): Rona Merdler-Rabinowicz, Anna Grinberg, Jeffrey M. Jacobson, Ido Somekh, Christoph Klein, Atar Lev, Salama Ihsan, Adib Habib, Raz Somech, and Amos J. Simon. Fetuin-a deficiency is associated with infantile cortical hyperostosis (caffey disease). Pediatric Research, 86:603-607, Jul 2019. URL: https://doi.org/10.1038/s41390-019-0499-0, doi:10.1038/s41390-019-0499-0. This article has 21 citations and is from a domain leading peer-reviewed journal.

  8. (merdlerrabinowicz2019fetuinadeficiencyis pages 4-5): Rona Merdler-Rabinowicz, Anna Grinberg, Jeffrey M. Jacobson, Ido Somekh, Christoph Klein, Atar Lev, Salama Ihsan, Adib Habib, Raz Somech, and Amos J. Simon. Fetuin-a deficiency is associated with infantile cortical hyperostosis (caffey disease). Pediatric Research, 86:603-607, Jul 2019. URL: https://doi.org/10.1038/s41390-019-0499-0, doi:10.1038/s41390-019-0499-0. This article has 21 citations and is from a domain leading peer-reviewed journal.

  9. (merdlerrabinowicz2019fetuinadeficiencyis pages 5-5): Rona Merdler-Rabinowicz, Anna Grinberg, Jeffrey M. Jacobson, Ido Somekh, Christoph Klein, Atar Lev, Salama Ihsan, Adib Habib, Raz Somech, and Amos J. Simon. Fetuin-a deficiency is associated with infantile cortical hyperostosis (caffey disease). Pediatric Research, 86:603-607, Jul 2019. URL: https://doi.org/10.1038/s41390-019-0499-0, doi:10.1038/s41390-019-0499-0. This article has 21 citations and is from a domain leading peer-reviewed journal.

Artifacts

Reference Validation

Checked with linkml-reference-validator 0.2.1.

Outcome Count
References checked 6
Resolved 3
Unresolved (possible confabulation) 3
Unverifiable 0
References weighed for topical relevance 3
On topic 1
Off topic 0

Unresolved references

These identifiers did not resolve to a record and may be fabricated. A lookup that failed for transport reasons is indistinguishable from one that failed because the record does not exist, so spot-check before acting on them:

  • DOI:10.1007/s00439-016-1756-5](https://doi.org/10.1007/s00439-016-1756-5 (2 mentions) - Identifier did not resolve to a record
  • DOI:10.3389/fnins.2024.1301865](https://doi.org/10.3389/fnins.2024.1301865 (2 mentions) - Identifier did not resolve to a record
  • DOI:10.1038/s41390-019-0499-0](https://doi.org/10.1038/s41390-019-0499-0 (2 mentions) - Identifier did not resolve to a record