Cardiofacioneurodevelopmental Syndrome

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Classifications

Harrison's Chapter

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Inheritance

1

Autosomal recessive HP:0000007

CFNDS requires two damaged CCDC32 alleles. Every family reported to date has been either consanguineous with a homozygous variant or has carried a biallelic deletion; heterozygous parents are unaffected.

Autosomal recessive inheritance

Show evidence (2 references)

PMID:41639596 SUPPORT Human Clinical

"Cardiofacioneurodevelopmental syndrome (CFNDS, MIM:619123) is a rare genetic disorder caused by bi-allelic pathogenic variants in CCDC32."

States the biallelic requirement directly, and anchors the OMIM identifier used for the NEC check.

PMID:32307552 SUPPORT Human Clinical

"we investigated the genetic and mechanistic cause of disease in two independent consanguineous families affected by overlapping craniofacial, cardiac, laterality and neurodevelopmental anomalies"

The founding report ascertained two consanguineous families, the classic setting for a recessive disorder.

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Mechanistic Hypotheses

2

AP-2 Assembly Chaperone / Clathrin-Mediated Endocytosis Model

ccdc32_ap2_endocytic_model CANONICAL

Evidence balance 3 support

The best-supported model is that CCDC32 is a dedicated assembly factor for the AP-2 clathrin adaptor complex, and that loss of CCDC32 causes a cell-wide deficit in clathrin-mediated endocytosis which in turn disrupts the signalling and receptor-trafficking events on which craniofacial, cardiac and neural development depend. The model is supported by an unbiased co-essentiality screen that first linked the gene to AP2, by biochemical reconstitution of the AAGAB-to-CCDC32 handover that builds AP2, by live-cell imaging showing that CCDC32 depletion destabilises clathrin-coated pits, and by structural work showing that CCDC32 deletion causes loss of all AP-2 subunits in vivo. It is further supported by the observation that all the disease alleles characterised to date truncate CCDC32 before the alpha-helix that mediates AP-2 binding.

Show evidence (3 references)

PMID:39145939 SUPPORT In Vitro

"We identified CCDC32 as another chaperone regulating AP2 assembly."

Establishes the core molecular role of the protein.

PMID:39145939 SUPPORT In Vitro

"The AP2-regulating function of CCDC32 is disrupted by a disease-causing mutation."

Directly connects the chaperone function to a disease allele rather than leaving the link inferential.

PMID:41489497 SUPPORT In Vitro

"These findings show that this loss-of-function nonsense mutation in CCDC32 abolishes its interactions with AP2 and inhibits CME, likely contributing to the development of CFNDS."

Tests a patient-derived truncation directly and reports that it abolishes AP2 binding and inhibits endocytosis.

Ciliary Contribution Model

ccdc32_ciliary_model ALTERNATIVE

Evidence balance 1 support

The original disease report proposed that CFNDS is at least partly a ciliopathy. Its authors noted that several patient features overlap defects common to ciliopathies, showed that zebrafish ccdc32 depletion recapitulates the human phenotypes, and showed that ccdc32 is required for normal cilium formation in zebrafish embryos and in mammalian cell culture. The presence of laterality anomalies in the original families is the clinical observation that most strongly favours a ciliary contribution, since laterality determination is a canonical motile-cilium-dependent process.

Classified ALTERNATIVE rather than CANONICAL, and carried on a PROVISIONAL pathophysiology node, because the finding has not been independently replicated since 2020, its own authors phrased the conclusion as ciliary defects being "at least partially" involved, and none of the three subsequent mechanistic papers on CCDC32 examined cilia at all. The two models are not mutually exclusive: AP-2 and clathrin-mediated endocytosis have documented roles in ciliary membrane trafficking, so an endocytic primary defect could produce a secondary ciliary phenotype.

Show evidence (1 reference)

PMID:32307552 SUPPORT Model Organism

"we show that ccdc32 is required for normal cilia formation in zebrafish embryos and mammalian cell culture, arguing that ciliary defects are at least partially involved in the pathomechanism of this disorder"

The single primary source for the ciliary model, stated by its own authors as a partial rather than complete explanation.

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Discussions and Knowledge Gaps

6

Do the craniofacial, cardiac and brain malformations of CFNDS arise from the endocytic consequences of failed AP-2 assembly, from a ciliary defect, or from both?

OPEN QUESTION OPEN ccdc32_ap2_versus_cilia

Attached to

pathophysiology#Defective Ciliogenesis pathophysiology#Deficient Clathrin-Mediated Endocytosis

The endocytic arm has by far the stronger molecular evidence: three independent structural and cell-biological studies published between 2024 and 2026 converge on CCDC32 being the assembly chaperone of AP-2, and a patient-derived truncation has been shown directly to abolish AP2 binding and inhibit endocytosis. The ciliary arm rests on one 2020 paper, has not been replicated, and was hedged by its own authors as being "at least partially" involved. But the endocytic arm has never been connected to a human malformation: its supporting argument for the developmental phenotype is the resemblance between CFNDS and mouse AP2-subunit knockouts, which is an analogy rather than a demonstration. Meanwhile the laterality anomalies in the founding families are hard to explain from endocytosis alone and are the canonical readout of motile-cilium dysfunction. The two models are not mutually exclusive, because clathrin-mediated endocytosis participates in ciliary membrane trafficking, so an endocytic primary defect could produce a secondary ciliary phenotype. Resolving this would require examining cilia in cells carrying a patient CCDC32 genotype, which no published study has done.

Both edges into the morphogenesis node are curated as INDIRECT_UNKNOWN_INTERMEDIATES precisely because of this gap.

Show evidence (2 references)

PMID:32307552 SUPPORT Model Organism

"arguing that ciliary defects are at least partially involved in the pathomechanism of this disorder"

The ciliary side of the question, stated by its own authors as a partial explanation, which is the hedge that keeps the question open.

PMID:41489497 SUPPORT In Vitro

"Our results suggest that the inability to bind mature AP2 and hence to be recruited to nascent CCSs inhibits critical early stages of CME and contributes to the development of CFNDS."

The endocytic side of the question, also phrased as a suggestion and a contribution rather than as a demonstrated cause.

Is CCDC32 a transient assembly chaperone that is released before AP-2 matures, or does it also bind the mature complex and act at clathrin-coated pits?

CONTROVERSY OPEN ccdc32_ap2_chaperone_mechanism

Attached to

pathophysiology#Failure of AP-2 Adaptor Complex Assembly pathophysiology#Clathrin-Coated Pit Destabilization

PMID:39145939 reconstituted an ordered handover in which AAGAB initiates assembly, CCDC32 forms a ternary template that recruits the remaining subunits, and CCDC32 is then released; those authors could not detect interaction between a C-terminally tagged CCDC32 and the mature AP2 complex. PMID:41489497 reports the opposite on that point, finding that CCDC32 binds full-length AP2 complexes in cells, is recruited to clathrin-coated pits, and is required for their stabilisation and invagination, and it notes the discrepancy explicitly. PMID:42234739 adds a third layer: in solution CCDC32 prevents assembly and actively disassembles AP-2 tetramers, and it is the presence of PIP2-containing membrane that permits assembly to complete, so the protein is proposed to be an inhibitor released by a membrane switch. The disagreement may be partly technical, since the tagging strategy differs between studies, but it is unresolved. For CFNDS the practical consequence is limited: on all three models, a truncation that removes the AP-2-binding helix is loss of function.

Show evidence (2 references)

PMID:42234739 SUPPORT In Vitro

"Unexpectedly, in solution, CCDC32 prevents complex assembly and actively disassembles AP-2 tetramers."

The third and most recent model, in which CCDC32 is inhibitory until membrane relieves the inhibition.

PMID:42234739 SUPPORT In Vitro

"We propose that the membrane acts as a molecular switch to release inhibitory interactions, allowing for full complex assembly to proceed."

The proposed reconciliation, which is itself a hypothesis.

Are the reported CFNDS alleles true nulls, or must they retain residual function for the pregnancy to be viable?

OPEN QUESTION OPEN ccdc32_hypomorph_versus_null

Attached to

pathophysiology#Biallelic CCDC32 Loss of Function

Complete loss of CCDC32 abolishes AP-2 complexes, and complete loss of AP2 has been reported to be embryonic lethal in Drosophila and zebrafish. The authors of PMID:41489497 therefore argue that the human CFNDS alleles must be hypomorphic rather than null, while acknowledging that nonsense-mediated decay could instead mean the truncated proteins are simply not expressed. One of the reported CFNDS conceptions was a terminated fetus, which is at least consistent with severe alleles being poorly tolerated. Distinguishing these possibilities requires measuring CCDC32 transcript and protein in patient cells, which has not been reported.

This question bears directly on whether a constitutive knockout would be a valid model of the human disease. No such model has been published, so the issue is recorded rather than resolved.

Show evidence (2 references)

PMID:41489497 SUPPORT In Vitro

"we suggest that the disease-associated CFNDS mutants are hypomorphic"

The hypomorph side of the question, phrased by its authors as a suggestion.

PMID:41489497 SUPPORT In Vitro

"While we cannot rule out nonsense-mediated decay and resulting loss of expression of the truncated human mutations"

The competing possibility, that the alleles are effectively null because the transcripts are degraded, acknowledged by the same authors.

Are the two large CCDC32 deletions a single recurrent allele generated by non-allelic homologous recombination at 15q15.1, or a founder allele, or coincidentally similar independent events?

KNOWLEDGE GAP OPEN ccdc32_recurrent_15q15_deletion

Attached to

pathophysiology#Biallelic CCDC32 Loss of Function

Three of the five reported CFNDS families carry a structural deletion rather than a point mutation, which is an unusually high proportion for a gene this small, and two of those deletions have near-identical breakpoints. ClinVar records the Abdalla allele as NC_000015.10:g.40529942_40562524del (VCV001690313) and the Fernandes da Rocha allele as NC_000015.10:g.(40529939_40562522)del (VCV002431643) - a difference of 3 bp at the proximal breakpoint and 2 bp at the distal one, between patients ascertained independently in Egypt/Hamburg and in Porto. Two mechanisms would explain that: a repeat-mediated recurrent rearrangement, in which flanking low-copy repeats at 15q15.1 make the same deletion arise repeatedly by non-allelic homologous recombination, or a shared founder haplotype. The two have opposite consequences for practice. A recurrent NAHR allele would mean the deletion arises de novo at appreciable frequency in any population, that a targeted breakpoint assay would be a worthwhile first-line test worldwide, and that carrier screening cannot be restricted by ancestry. A founder allele would confine that reasoning to one population. Nothing published distinguishes them: no segmental-duplication analysis of the interval has been reported, neither paper reports a breakpoint junction sequence, no haplotype has been typed across the two families, and the difference of a few base pairs may be nothing more than differing CNV-calling resolution between two laboratories rather than a real difference in the alleles. Resolving this needs breakpoint-junction sequencing in both families plus a repeat-content analysis of 15q15.1; both are straightforward and neither has been done.

THIS IS A HYPOTHESIS, NOT A FINDING, AND IS CURATED AS A KNOWLEDGE GAP FOR THAT REASON. The breakpoint coordinates quoted in the rationale are ClinVar record fields retrieved from the NCBI eutils ClinVar esummary endpoint on 2026-08-01, not statements made by either publication; the Fernandes da Rocha report (PMID:38818818) is indexed in PubMed without an abstract and its full text is not in the reference cache, so no evidence item can quote its breakpoints and the inference is explicitly not attributed to its authors. The ClinVar coordinates for that allele are additionally parenthesised, which in HGVS notation means the breakpoints are uncertain - so the apparent 2-to-3-bp difference may not be a real difference at all. The lead was raised in section 4.2 of the deep-research artifact for this entry and is recorded here rather than dropped, with its provenance and its unresolved status stated, because it is testable and consequential.

Show evidence (2 references)

PMID:35451546 SUPPORT Human Clinical

"We report a 9-year-old female patient with CFNDS caused by a homozygous 32,583-bp deletion affecting CCDC32."

The first of the two deletion alleles whose breakpoints are being compared, and the only one whose size is stated in a quotable published text.

PMID:38818818 SUPPORT Human Clinical

"A novel homozygous deletion in CCDC32 gene causing cardiofacioneurodevelopmental syndrome: the fourth patient reported."

Establishes that a second, independently ascertained homozygous CCDC32 deletion exists. The quoted text is the article title, because this report is indexed without an abstract; see entry note (5). Note that the authors call their allele "novel", which is a claim of independence rather than of recurrence, and that they had no way to compare breakpoints with the earlier report.

Why is expressivity so variable between individuals when every reported allele is a complete loss of function?

OPEN QUESTION OPEN ccdc32_expressivity_with_loss_of_function_alleles

Attached to

pathophysiology#Biallelic CCDC32 Loss of Function phenotypes#Hypertelorism

Every CFNDS allele reported to date is a truncation or a deletion, so there is no obvious allelic-series explanation for phenotypic differences. Yet the two index individuals differed in opposite directions on the same midline measurement, one being hypoteloric and the other hyperteloric, and the cardiac phenotype ranged from an atrioventricular canal defect with asplenia and abdominal situs inversus in one to an isolated ventricular septal defect with pulmonic stenosis in the other. Candidate explanations are unmapped modifier loci, differences in residual transcript escaping nonsense-mediated decay, and stochastic variation in a threshold-sensitive developmental process. None has been tested. The practical consequence is that no genotype-based prognostic counselling is possible.

The hypertelorism/hypotelorism discordance is taken from the HPO annotation for OMIM:619123 (both at 1/2, source PMID:32307552) and from the separately evidenced hypertelorism in PMID:35451546; it is recorded in the `notes:` of the two corresponding phenotypes rather than as an evidence item, because the underlying counts come from a full text that is not in the reference cache.

What is the true frequency of each CFNDS feature, and what is the natural history beyond childhood?

KNOWLEDGE GAP OPEN ccdc32_phenotype_denominator_gap

Fewer than ten affected individuals have been reported, in four separate papers, with non-uniform investigation: not every patient is documented as having had brain imaging, echocardiography or audiometry, so an apparent absence of a feature may be an absence of testing. No prospective natural history study, no survival data, no adult outcome and no population prevalence or carrier frequency exists. This entry therefore asserts no frequency band on any phenotype and no prevalence rate. The gap will close only through a multicentre case collection, which the diagnostic difficulty documented in PMID:41639596 suggests is likely to keep growing as RNA sequencing enters routine practice.

Show evidence (1 reference)

PMID:41639596 SUPPORT Human Clinical

"So far, CFNDS has only been described in four living individuals and one terminated fetus from four families"

Quantifies the denominator problem: no frequency or natural-history claim can be made from a cohort of this size.

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Pathophysiology

6

Biallelic CCDC32 Loss of Function

Homozygous or compound-heterozygous loss-of-function variants in CCDC32 (also known as C15orf57, at 15q15.1) remove or truncate a small 185-amino-acid coiled-coil protein. The alleles characterised to date are frameshift or nonsense variants that terminate translation after the first 9, 54 or 80 residues, and whole-gene or multi-exon deletions. All of the characterised truncations lie upstream of the alpha-helix formed by residues 78 to 98, which is the segment required for binding the AP-2 alpha subunit.

CCDC32 hgnc:28295

AP-2 adaptor complex binding GO:0035612 ∅ ABSENT

Downstream

Failure of AP-2 Adaptor Complex Assembly CCDC32 is the assembly chaperone that templates AP-2 tetramer formation, so its loss is directly a failure of that assembly step.

Defective Ciliogenesis Depletion of the zebrafish orthologue impairs cilium formation, but no molecular route from the CCDC32 defect to the ciliary phenotype has been identified, and it is not known whether the ciliary effect is downstream of the endocytic one.

Show evidence (3 references)

PMID:32307552 SUPPORT Human Clinical

"Using whole exome sequencing, we identified homozygous frameshift CCDC32 variants in three affected individuals."

The founding identification of biallelic loss-of-function alleles.

PMID:41489497 SUPPORT Human Clinical

"Clinical genome sequencing of three patients with cardio-facio-neuro-developmental syndrome (CFNDS) revealed three homozygous nonsense mutations that only express the first 9, 54, and 80 aa of CCDC32, respectively"

Specifies the residue positions at which the reported disease alleles truncate the protein.

PMID:41489497 SUPPORT In Vitro

"Deletion of aa78-98 in CCDC32, corresponding to a predicted alpha-helix, abrogates AP2 binding"

Identifies the protein segment that all reported disease truncations remove, explaining why they are loss of function for AP-2 binding.

Failure of AP-2 Adaptor Complex Assembly

AP-2 is a heterotetramer of alpha, beta2, mu2 and sigma2 subunits and is the principal cargo adaptor of clathrin-mediated endocytosis. Its assembly is a chaperoned, ordered process: AAGAB first stabilises the alpha and sigma2 subunits, CCDC32 then displaces AAGAB to form an alpha-sigma2-CCDC32 ternary template, and that template sequentially recruits mu2 and beta2 before CCDC32 is released. Without CCDC32 the handover cannot occur and cells lose AP-2 complexes.

AP-2 clathrin adaptor complex GO:0030122

AP-2 adaptor complex GO:0030122

Downstream

Clathrin-Coated Pit Destabilization AP-2 nucleates and stabilises nascent clathrin-coated pits, so depletion of assembled AP-2 is directly a coated-pit stability defect.

Show evidence (3 references)

PMID:39145939 SUPPORT In Vitro

"These findings demonstrate that AP2 is assembled by a handover mechanism switching from AAGAB-based initiation complexes to CCDC32-based template complexes."

A complete sentence stating the ordered, chaperoned nature of AP2 assembly and CCDC32's position in it, which is what this edge asserts. This replaces an earlier mid-clause fragment ("Here, we found that AAGAB initiates AP2 assembly by stabilizing its") that had been truncated to avoid quoting the Greek-lettered subunit names; the substituted sentence carries the same claim, is ASCII throughout, and does not end mid-predicate.

PMID:42234739 SUPPORT In Vitro

"coiled-coil domain-containing protein 32 (CCDC32), whose deletion causes loss of all AP-2 subunits in vivo"

States the consequence of losing CCDC32 for the complex as a whole, which is the step this node models.

PMID:33859415 SUPPORT In Vitro

"We also show that C15orf57 encodes a protein that binds the AP2 complex, localizes to clathrin-coated pits and enables efficient transferrin uptake."

The unbiased co-essentiality screen that first assigned CCDC32 (C15orf57) to the AP2 module.

Clathrin-Coated Pit Destabilization

Loss of CCDC32 function leaves the plasma membrane populated by flat, short-lived clathrin assemblies that fail to curve and invaginate. Invagination of the nascent coated pit is the checkpoint that determines whether a pit matures productively or aborts, so this is the point at which the molecular defect becomes a cell-biological one.

Clathrin-coated pit GO:0005905

Downstream

Deficient Clathrin-Mediated Endocytosis Coated pits that cannot invaginate cannot become coated vesicles, so cargo internalisation falls.

Show evidence (1 reference)

PMID:41489497 SUPPORT In Vitro

"We show by quantitative live cell imaging that siRNA-mediated knockdown of CCDC32, a poorly characterized endocytic accessory protein, leads to the accumulation of unstable flat clathrin assemblies."

Direct live-cell demonstration of the coated-pit phenotype caused by loss of CCDC32.

Deficient Clathrin-Mediated Endocytosis

The functional read-out of the coated-pit defect is reduced receptor-mediated internalisation, measured in the primary literature as impaired transferrin receptor uptake. Clathrin-mediated endocytosis controls the surface residence and signalling output of most developmental receptors, and its failure is the proposed bridge between the molecular lesion and the malformation phenotype.

Clathrin-dependent endocytosis GO:0072583 ↓ DECREASED

Downstream

Disrupted Craniofacial, Cardiac and Neural Morphogenesis No specific receptor, signalling pathway or cell population has been shown to link the endocytic deficit to the human malformations. The supporting argument is comparative: mice lacking individual AP2 subunits develop cleft palate and cardiac defects, and the clinical features of CCDC32 loss resemble those of AP2 loss-of-function mutations.

Show evidence (2 references)

PMID:33859415 SUPPORT In Vitro

"We also show that C15orf57 encodes a protein that binds the AP2 complex, localizes to clathrin-coated pits and enables efficient transferrin uptake."

Establishes that CCDC32 is required for efficient receptor-mediated internalisation, the functional read-out modelled by this node.

PMID:35451546 PARTIAL Model Organism

"Cleft palate and cardiac defects observed in mice deficient of different AP2 subunits support a CCDC32 function in the AP2 complex."

The comparative argument that links AP2 dysfunction to the CFNDS malformation pattern. Marked PARTIAL and MODEL_ORGANISM because it is a secondhand report of mouse data inside a human case report, and because the mice are AP2-subunit mutants rather than Ccdc32 mutants.

Defective Ciliogenesis

An alternative, and possibly parallel, arm of the pathomechanism. Depletion of ccdc32 in zebrafish embryos and in mammalian cell culture impairs cilium formation. Because primary and motile cilia govern Hedgehog signalling, left-right patterning and craniofacial neural-crest development, a ciliary defect would account for the laterality anomalies and for the overlap of the CFNDS phenotype with recognised ciliopathies.

Cilium assembly GO:0060271 ↓ DECREASED

Downstream

Disrupted Craniofacial, Cardiac and Neural Morphogenesis Ciliary signalling defects are a recognised route to craniofacial, cardiac and laterality malformations, but this route has not been demonstrated for CCDC32 in human tissue.

Show evidence (2 references)

PMID:32307552 SUPPORT Model Organism

"we show that ccdc32 is required for normal cilia formation in zebrafish embryos and mammalian cell culture, arguing that ciliary defects are at least partially involved in the pathomechanism of this disorder"

The sole primary evidence for the ciliary arm, quoted with the authors own hedge intact.

PMID:32307552 PARTIAL Human Clinical

"Because some of the patient phenotypes overlap defects common to ciliopathies, we asked if loss of CCDC32 might contribute to the dysfunction of this organelle."

Records the clinical observation that motivated the ciliary hypothesis. PARTIAL because phenotypic overlap is suggestive, not demonstrative.

Disrupted Craniofacial, Cardiac and Neural Morphogenesis

The convergent developmental outcome. Failure of the endocytic and possibly ciliary machinery during embryogenesis produces the syndrome: failure of fusion of the facial prominences giving bilateral cleft lip and palate, congenital cardiac malformation, disturbed left-right patterning, and maldevelopment of midline and posterior-fossa brain structures giving corpus-callosum hypoplasia and cerebellar hypoplasia.

Determination of left/right symmetry GO:0007368 ⚠ ABNORMAL

Show evidence (2 references)

PMID:35451546 SUPPORT Human Clinical

"The cardiofacioneurodevelopmental syndrome (CFNDS) is characterized by craniofacial anomalies including bilateral cleft lip and palate, cardiac, skeletal, and neurodevelopmental features and additional variable manifestations."

Defines the multi-system malformation outcome that this terminal node represents.

PMID:32307552 SUPPORT Model Organism

"Functional analysis in a zebrafish model revealed that ccdc32 depletion recapitulates the human phenotypes."

Shows that depleting the orthologue in a vertebrate embryo reproduces the multi-system malformation pattern.

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Pathograph

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Phenotypes

26

Cardiovascular 3

Ventricular septal defect Ventricular septal defect HP:0001629

Onset: CONGENITAL

NO EVIDENCE ITEM. Sourced from the HPO annotation for OMIM:619123 retrieved on 2026-08-01, which records Ventricular septal defect at 1/2 with source PMID:32307552, from that paper's full text. See entry note (10).

Pulmonic stenosis Pulmonic stenosis HP:0001642

Onset: CONGENITAL

NO EVIDENCE ITEM. Sourced from the HPO annotation for OMIM:619123 retrieved on 2026-08-01, which records Pulmonic stenosis at 1/2 with source PMID:32307552, from that paper's full text. See entry note (10).

Congenital cardiac anomaly Abnormal heart morphology HP:0001627

Onset: CONGENITAL

Named in the original report and carried forward by the 2026 review. Not every reported individual is documented as having had echocardiography, which is one reason no frequency band is asserted: see entry note (4).

Show evidence (2 references)

PMID:32307552 SUPPORT Human Clinical

"we investigated the genetic and mechanistic cause of disease in two independent consanguineous families affected by overlapping craniofacial, cardiac, laterality and neurodevelopmental anomalies"

Documents cardiac anomalies in the founding families.

PMID:41639596 SUPPORT Human Clinical

"the clinical phenotype can include microcephaly, facial malformations, developmental delay, cerebellar hypoplasia, and cardiac anomalies"

The 2026 review confirms cardiac anomalies as a recurring feature.

Digestive 1

Feeding difficulties in infancy Feeding difficulties in infancy HP:0008872

Onset: INFANTILE

NO EVIDENCE ITEM. Sourced from the HPO annotation for OMIM:619123 retrieved on 2026-08-01, which records Feeding difficulties in infancy at 2/2 with source PMID:32307552, from that paper's full text. See entry note (10).

Ear 1

Conductive hearing impairment Conductive hearing impairment HP:0000405

Show evidence (1 reference)

PMID:35451546 SUPPORT Human Clinical

"She had bilateral conductive hearing loss, small hands and feet, and finger abnormalities."

Direct documentation in a genotyped patient.

Eye 2

Hypertelorism Hypertelorism HP:0000316

Severity: SEVERE

Interorbital distance is DISCORDANT across the reported individuals. The HPO annotation for OMIM:619123 records Hypertelorism at 1/2 AND Hypotelorism at 1/2 from the same two-patient source, meaning the two index individuals deviated in opposite directions on the same measurement, and PMID:35451546 then reported marked hypertelorism in a third, unrelated patient. Both directions are curated as separate phenotypes rather than being merged. This entry does not claim a direction is typical.

Show evidence (1 reference)

PMID:35451546 SUPPORT Human Clinical

"The patient had intellectual disability, marked hypertelorism, bilateral cleft lip and palate, and short stature."

Documents hypertelorism, and its severity qualifier, in a genotyped patient.

Hypotelorism Hypotelorism HP:0000601

NO EVIDENCE ITEM. Sourced from the HPO annotation for OMIM:619123 retrieved on 2026-08-01, which records Hypotelorism at 1/2 with source PMID:32307552. The count is derived from the full text of that paper, whose abstract is the only part available in the reference cache and which does not mention interorbital distance. See entry note (10).

Genitourinary 1

Cryptorchidism Cryptorchidism HP:0000028

NO EVIDENCE ITEM. Sourced from the HPO annotation for OMIM:619123 retrieved on 2026-08-01, which records Cryptorchidism at 1/1 with source PMID:32307552, from that paper's full text. The 1/1 denominator is the number of individuals in whom the sex-limited finding could be assessed. See entry note (10).

Head and Neck 4

Cleft lip Cleft lip HP:0410030

Onset: CONGENITAL

Reported in all three individuals known at the time of PMID:35451546, and named as part of the disease definition in that paper. No frequency band is asserted: see entry note (4).

Show evidence (2 references)

PMID:35451546 SUPPORT Human Clinical

"We describe a core phenotype comprising developmental delay and bilateral cleft lip and palate in the three individuals with CFNDS."

Designates bilateral cleft lip and palate as one of the two core features of the syndrome.

PMID:35451546 SUPPORT Human Clinical

"The patient had intellectual disability, marked hypertelorism, bilateral cleft lip and palate, and short stature."

Documents the finding in the individually reported patient.

Cleft palate Cleft palate HP:0000175

Onset: CONGENITAL

Reported in all three individuals known at the time of PMID:35451546. No frequency band is asserted: see entry note (4).

Show evidence (1 reference)

PMID:35451546 SUPPORT Human Clinical

"The cardiofacioneurodevelopmental syndrome (CFNDS) is characterized by craniofacial anomalies including bilateral cleft lip and palate, cardiac, skeletal, and neurodevelopmental features and additional variable manifestations."

Names bilateral cleft lip and palate as the defining craniofacial anomaly.

Abnormal facial shape Abnormal facial shape HP:0001999

Show evidence (2 references)

PMID:41639596 SUPPORT Human Clinical

"the clinical phenotype can include microcephaly, facial malformations, developmental delay, cerebellar hypoplasia, and cardiac anomalies"

Lists facial malformations among the recurring features of the syndrome.

PMID:35451546 SUPPORT Human Clinical

"Variable abnormalities of the face, brain, heart, fingers, and toes and postnatal growth retardation or microcephaly can be present."

Records facial abnormality as a variable, non-obligate feature.

Microcephaly Microcephaly HP:0000252

Show evidence (2 references)

PMID:41639596 SUPPORT Human Clinical

"the clinical phenotype can include microcephaly, facial malformations, developmental delay, cerebellar hypoplasia, and cardiac anomalies"

Lists microcephaly among the recurring features.

PMID:35451546 PARTIAL Human Clinical

"Variable abnormalities of the face, brain, heart, fingers, and toes and postnatal growth retardation or microcephaly can be present."

Marked PARTIAL because this sentence presents microcephaly as one of two alternative growth-related findings rather than asserting it in any specific patient.

Limbs 2

Small hand Small hand HP:0200055

Show evidence (1 reference)

PMID:35451546 SUPPORT Human Clinical

"She had bilateral conductive hearing loss, small hands and feet, and finger abnormalities."

Direct documentation in a genotyped patient.

Short foot Short foot HP:0001773

Show evidence (1 reference)

PMID:35451546 SUPPORT Human Clinical

"She had bilateral conductive hearing loss, small hands and feet, and finger abnormalities."

Direct documentation in a genotyped patient.

Nervous System 5

Global developmental delay Global developmental delay HP:0001263

Named as core in PMID:35451546 across the three individuals then known, and listed again among the recurring features in the 2026 review. No frequency band is asserted: see entry note (4).

Show evidence (2 references)

PMID:35451546 SUPPORT Human Clinical

"We describe a core phenotype comprising developmental delay and bilateral cleft lip and palate in the three individuals with CFNDS."

Designates developmental delay as one of the two core features.

PMID:41639596 SUPPORT Human Clinical

"the clinical phenotype can include microcephaly, facial malformations, developmental delay, cerebellar hypoplasia, and cardiac anomalies"

The 2026 review carries developmental delay forward as a recurring feature.

Intellectual disability Intellectual disability HP:0001249

Documented in one individually described patient. Because the syndrome is congenital and the reported cohort is largely young, the proportion of affected individuals old enough for a formal cognitive assessment is small, which is a further reason no frequency band is asserted.

Show evidence (1 reference)

PMID:35451546 SUPPORT Human Clinical

"The patient had intellectual disability, marked hypertelorism, bilateral cleft lip and palate, and short stature."

Direct documentation of intellectual disability in a genotyped patient.

Cerebellar vermis hypoplasia Cerebellar vermis hypoplasia HP:0001320

NO EVIDENCE ITEM. Sourced from the HPO annotation for OMIM:619123 retrieved on 2026-08-01, which records Cerebellar vermis hypoplasia at 1/1 with source PMID:32307552, from that paper's full text. The 1/1 rather than 1/2 denominator reflects that only one individual had the relevant imaging. See entry note (10). The broader Cerebellar hypoplasia phenotype in this entry IS separately evidenced from PMID:41639596.

Hypoplasia of the corpus callosum Hypoplasia of the corpus callosum HP:0002079

Show evidence (1 reference)

PMID:35451546 SUPPORT Human Clinical

"Brain imaging disclosed hypoplastic corpus callosum."

Direct imaging documentation in a genotyped patient.

Cerebellar hypoplasia Cerebellar hypoplasia HP:0001321

Show evidence (1 reference)

PMID:41639596 SUPPORT Human Clinical

"the clinical phenotype can include microcephaly, facial malformations, developmental delay, cerebellar hypoplasia, and cardiac anomalies"

The review that pooled the published cases lists cerebellar hypoplasia as part of the phenotype.

Growth 2

Postnatal growth retardation Postnatal growth retardation HP:0008897

Show evidence (1 reference)

PMID:35451546 SUPPORT Human Clinical

"Variable abnormalities of the face, brain, heart, fingers, and toes and postnatal growth retardation or microcephaly can be present."

Names postnatal growth retardation as a variable feature.

Short stature Short stature HP:0004322

Show evidence (1 reference)

PMID:35451546 SUPPORT Human Clinical

"The patient had intellectual disability, marked hypertelorism, bilateral cleft lip and palate, and short stature."

Direct documentation in a genotyped patient.

Other 5

Atrioventricular canal defect Atrioventricular canal defect HP:0006695

Onset: CONGENITAL

NO EVIDENCE ITEM. Sourced from the HPO annotation for OMIM:619123 retrieved on 2026-08-01, which records Atrioventricular canal defect at 1/2 with source PMID:32307552, from that paper's full text. See entry note (10).

Asplenia Asplenia HP:0001746

Onset: CONGENITAL

NO EVIDENCE ITEM. Sourced from the HPO annotation for OMIM:619123 retrieved on 2026-08-01, which records Asplenia at 1/2 with source PMID:32307552, from that paper's full text. See entry note (10). Despite the lack of a quotable snippet this finding is promoted into the structured phenotype list because it directly changes management; the corresponding treatment entry is Antimicrobial prophylaxis and immunisation for asplenia.

Abdominal situs inversus Abdominal situs inversus HP:0003363

Onset: CONGENITAL

NO EVIDENCE ITEM. Sourced from the HPO annotation for OMIM:619123 retrieved on 2026-08-01, which records Abdominal situs inversus at 1/2 with source PMID:32307552, from that paper's full text. See entry note (10). The general laterality claim IS separately evidenced, on the Laterality anomaly phenotype.

Laterality anomaly Heterotaxy HP:0030853

Reported only by PMID:32307552 and not restated in the abstracts of the subsequent case reports or of the 2026 review, so it may be a feature of the original families rather than a consistent feature of the syndrome.

Show evidence (1 reference)

PMID:32307552 PARTIAL Human Clinical

"we investigated the genetic and mechanistic cause of disease in two independent consanguineous families affected by overlapping craniofacial, cardiac, laterality and neurodevelopmental anomalies"

Documents laterality anomalies in the founding families. Marked PARTIAL because the abstract names the category without specifying whether the finding was situs inversus, situs ambiguus or an isolated visceral discordance, so the binding to the general heterotaxy term is the closest honest fit rather than an exact match.

Abnormal finger morphology Abnormal finger morphology HP:0001167

Show evidence (2 references)

PMID:35451546 SUPPORT Human Clinical

"She had bilateral conductive hearing loss, small hands and feet, and finger abnormalities."

Direct documentation in a genotyped patient.

PMID:35451546 SUPPORT Human Clinical

"Variable abnormalities of the face, brain, heart, fingers, and toes and postnatal growth retardation or microcephaly can be present."

Records digital anomalies as a variable feature of the syndrome.

🧬

Genetic Associations

1

CCDC32

Gene: CCDC32 hgnc:28295 relationship_type: CAUSATIVE variant_origin: GERMLINE

Autosomal recessive

Show evidence (3 references)

PMID:32307552 SUPPORT Human Clinical

"Using whole exome sequencing, we identified homozygous frameshift CCDC32 variants in three affected individuals."

The founding gene-disease association.

PMID:35451546 SUPPORT Human Clinical

"Whole-exome sequencing revealed homozygous loss-of-function variants in CCDC32 (alternative name: C15orf57) in both previously described patients."

Independent confirmation of the gene-disease relationship, and the source for the alternative gene symbol recorded in the notes.

PMID:38818818 SUPPORT Human Clinical

"A novel homozygous deletion in CCDC32 gene causing cardiofacioneurodevelopmental syndrome: the fourth patient reported."

A fourth independent family. This article is indexed in PubMed WITHOUT an abstract, so the cached reference body contains only the bibliographic header; the quoted text is the article title itself, which is why no clinical detail from this report is asserted anywhere in this entry. See entry note (5).

💊

Medical Actions

10

Antimicrobial prophylaxis and immunisation for asplenia

Action: Pharmacotherapy NCIT:C15986

In the subset of individuals with asplenia, lifelong antibiotic prophylaxis (conventionally penicillin), an asplenia immunisation schedule against encapsulated organisms, and a low threshold for empiric treatment of febrile illness are indicated. This is the only pharmacological intervention in the syndrome with a specific indication rather than a purely symptomatic one, and it is the reason abdominal imaging for spleen and situs belongs in the baseline evaluation. It follows generic asplenia protocols; no CFNDS-specific protocol exists.

Target Phenotypes: Asplenia HP:0001746

Cleft palate repair

Action: palatorrhaphy Ontology label: Palatorrhaphy NCIT:C168380

Surgical closure of the palatal cleft (palatoplasty/palatorrhaphy), typically at around 9 to 18 months and timed to speech development, within a multidisciplinary cleft team that also manages feeding, hearing and dentition. This is standard cleft care and is not specific to CFNDS; no CFNDS-specific surgical outcome data exist. The timing relative to speech acquisition is why this treatment is coordinated with the speech and language therapy entry below.

Target Phenotypes: Cleft palate HP:0000175

Cleft lip repair

Action: cleft lip repair (cheiloplasty) Ontology label: Surgical Procedure NCIT:C15329

Surgical closure of the cleft lip (cheiloplasty), conventionally in the first months of life, addressing lip competence, feeding and facial appearance. Split from palatal repair because the two procedures have different timing, different functional targets and different NCIT identities; NCIT has no cheiloplasty-specific clinical-action term reachable from NCIT:C25218 that `just validate-terms` accepts, so the generic surgical-procedure term is retained here while the palatal arm uses the specific term. Standard cleft care, not CFNDS-specific.

Target Phenotypes: Cleft lip HP:0410030

Nutritional and feeding support in infancy

Action: nutritional support Ontology label: Nutritional Support NCIT:C15433

Feeding difficulties in infancy are reported in every fully described CFNDS infant and have two convergent causes here: the orofacial cleft itself, which prevents an effective seal, and the neurodevelopmental component. Management is cleft-specific feeding equipment and positioning, calorie supplementation and growth monitoring, escalating to gastrostomy if feeding failure is severe. This closes the loop on the promoted Feeding difficulties in infancy phenotype: it was promoted from the HPO annotation set under the "changes management" rule in entry note (10), and this is the management it changes. Generic supportive care, not CFNDS-specific.

Target Phenotypes: Feeding difficulties in infancy HP:0008872

Orchidopexy for cryptorchidism

Action: orchiopexy Ontology label: Orchiopexy NCIT:C111066

Surgical orchidopexy for undescended testis, conventionally between 6 and 18 months of age, following general paediatric urology practice rather than any CFNDS-specific protocol. Included because cryptorchidism was promoted into the `phenotypes:` list under the "changes management" rule in entry note (10), and this is the management it changes: the phenotype is only worth recording if it triggers examination and referral within the window in which orchidopexy protects fertility and reduces malignancy risk. Reported in one of the two index individuals (HPO annotation 1/1); no CFNDS-specific urological outcome data exist.

Target Phenotypes: Cryptorchidism HP:0000028

Audiological surveillance and hearing support

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

Bilateral conductive hearing loss has been reported and is expected in a child with cleft palate. Regular audiometry, treatment of middle-ear effusion and amplification where indicated protect the speech and language development that is already at risk from the neurodevelopmental component.

Speech and language therapy

Action: speech therapy Ontology label: Speech Language Therapy NCIT:C159273

A high priority in this syndrome specifically, because three separate contributors converge on speech: the palatal cleft itself, the conductive hearing loss that accompanies it, and the global developmental delay. Therapy should be coordinated with the timing of palatoplasty and with audiological management.

Developmental and educational therapy

Action: rehabilitation Ontology label: Rehabilitation NCIT:C15315

Early intervention, physical and occupational therapy, and an individualised educational programme, directed at the developmental delay and intellectual disability. Symptomatic and supportive only.

Cardiac evaluation and management

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

Echocardiography at diagnosis, with cardiology follow-up and surgical repair of any structural lesion according to standard congenital heart disease practice. No lesion pattern specific to CFNDS has been defined.

Genetic counselling

Action: genetic counseling Ontology label: Genetic Counseling NCIT:C15240

CFNDS is autosomal recessive, so unaffected carrier parents have a 25% recurrence risk in each pregnancy. Several reported families were consanguineous. Once the familial alleles are known, carrier testing and prenatal or preimplantation testing become available. Counselling should note that structural deletions are a common allele class and that a targeted deletion assay, rather than sequencing alone, may be needed for accurate carrier testing.

🔀

Differential Diagnoses

3

Conditions with similar clinical presentations that must be differentiated from Cardiofacioneurodevelopmental Syndrome:

Cardiofaciocutaneous syndrome MONDO:0015280

Overlapping Features A RASopathy caused by heterozygous gain-of-function variants in BRAF, MAP2K1, MAP2K2 or KRAS. It is included here primarily as a NAMING hazard rather than a close clinical mimic: "cardiofaciocutaneous" and "cardiofacioneurodevelopmental" differ by one word element, both abbreviate to a CF acronym, and a literature search or an automated entity resolver can silently substitute one for the other. Clinically the two do share craniofacial dysmorphism, congenital heart disease, growth retardation and intellectual disability, so the distinction also matters at the bedside. The discriminators are the ectodermal features and the inheritance pattern.

Distinguishing Features

Autosomal dominant, usually de novo, versus autosomal recessive for CFNDS
Caused by RAS-MAPK pathway genes (BRAF, MAP2K1, MAP2K2, KRAS), not CCDC32
Hyperkeratotic skin and sparse curly hair are cardinal, and have not been reported in CFNDS
Bilateral cleft lip and palate is the core craniofacial feature of CFNDS but is not characteristic of cardiofaciocutaneous syndrome
Pulmonic stenosis and hypertrophic cardiomyopathy are the characteristic RASopathy cardiac lesions

Show evidence (3 references)

PMID:20301365 SUPPORT Human Clinical

"CLINICAL CHARACTERISTICS: Cardiofaciocutaneous (CFC) syndrome is characterized by cardiac abnormalities (pulmonic stenosis and other valve dysplasias, septal defects, hypertrophic cardiomyopathy, rhythm disturbances), distinctive craniofacial appearance, and cutaneous abnormalities"

The GeneReviews definition of the differential, showing that the cutaneous component is cardinal to it and absent from CFNDS.

PMID:20301365 SUPPORT Human Clinical

"The diagnosis of CFC syndrome is established in a proband with suggestive clinical findings by the identification of a heterozygous pathogenic variant in BRAF, MAP2K1, MAP2K2, or KRAS by molecular genetic testing."

Establishes the genetic discriminator: heterozygous RAS-MAPK pathway variants rather than biallelic CCDC32 variants.

PMID:20301365 SUPPORT Human Clinical

"CFC syndrome is inherited in an autosomal dominant manner."

Establishes the inheritance discriminator.

AP2M1-related intellectual developmental disorder with seizures Not Yet Curated MONDO:0032823

Overlapping Features Caused by heterozygous de novo variants in AP2M1, which encodes the mu2 subunit of the same AP-2 complex that CCDC32 assembles. This is the mechanistically closest human disorder: it disrupts the same endpoint from inside the complex rather than from the chaperone that builds it. The phenotypes diverge, which is itself informative, since AP2M1 disease is a dominant epileptic-encephalopathy-like neurodevelopmental phenotype without the orofacial clefting and laterality anomalies that define CFNDS.

Distinguishing Features

Autosomal dominant de novo, versus autosomal recessive for CFNDS
Caused by AP2M1 (HGNC:564), an AP-2 subunit, rather than CCDC32, the AP-2 assembly chaperone
Seizures are a defining feature, and have not been reported in CFNDS
Orofacial clefting, laterality anomalies and congenital cardiac malformation are not features

Show evidence (2 references)

PMID:31104773 SUPPORT Human Clinical

"We subsequently found the same de novo variant in two individuals with neurodevelopmental disorders and generalized epilepsy in a cohort of 2,310 individuals who underwent diagnostic whole-exome sequencing."

Establishes the de novo dominant inheritance and the epilepsy-dominated phenotype that discriminate this disorder from CFNDS.

PMID:31104773 SUPPORT Human Clinical

"We identified a de novo c.508C>T (p.Arg170Trp) variant in AP2M1 in two individuals with a phenotypic similarity that was higher than expected by chance (p = 0.003) and a phenotype related to epilepsy with myoclonic-atonic seizures."

Names the recurrent allele and the seizure phenotype, neither of which has a counterpart in CFNDS.

Ciliopathy with craniofacial, cardiac and laterality involvement

Overlapping Features The founding report explicitly framed CFNDS as overlapping the ciliopathies, on the basis of the laterality anomalies and the craniofacial and brain findings. In practice a child with orofacial clefting, a congenital cardiac lesion, situs abnormality and posterior-fossa anomaly will be worked up for the ciliopathy spectrum, and CCDC32 should be in that differential rather than outside it. No single MONDO grouping term is bound here because the candidate entities span several distinct disorders rather than one, and picking any one of them would assert a specific alternative diagnosis that the source does not support.

Distinguishing Features

Retinal degeneration, cystic kidney disease and postaxial polydactyly are cardinal in the classic ciliopathies and have not been reported in CFNDS
Bilateral cleft lip and palate is the core CFNDS feature and is not typical of the classic ciliopathies
CFNDS is caused by CCDC32, which is an AP-2 assembly chaperone rather than a structural or transport component of the cilium

Show evidence (1 reference)

PMID:32307552 SUPPORT Human Clinical

"Because some of the patient phenotypes overlap defects common to ciliopathies, we asked if loss of CCDC32 might contribute to the dysfunction of this organelle."

The authors themselves note the phenotypic overlap with ciliopathies, which is the reason this differential is listed.

{ }

Source YAML

click to show

name: Cardiofacioneurodevelopmental Syndrome
creation_date: '2026-08-01T00:00:00Z'
category: Mendelian
synonyms:
- CFNDS
- cardio-facio-neuro-developmental syndrome
- CCDC32-related cardiofacioneurodevelopmental syndrome
- C15orf57-related multiple congenital anomaly syndrome
description: >-
  Cardiofacioneurodevelopmental syndrome (CFNDS) is an ultra-rare autosomal
  recessive multiple congenital anomaly syndrome caused by biallelic
  loss-of-function variants in CCDC32 (formerly C15orf57). Its recurring core is
  developmental delay together with bilateral cleft lip and palate, on a
  background of variable craniofacial, cardiac, laterality, brain, digital and
  growth anomalies. Reported brain findings include hypoplasia of the corpus
  callosum, cerebellar hypoplasia and microcephaly. CCDC32 encodes a small
  185-amino-acid coiled-coil protein that acts as an assembly chaperone for the
  AP-2 clathrin adaptor complex, the principal cargo adaptor of
  clathrin-mediated endocytosis; the disease alleles reported to date truncate
  the protein before the alpha-helix required for AP-2 binding. A parallel
  ciliary arm of the pathomechanism was proposed in the original report, in
  which zebrafish ccdc32 depletion recapitulated the human phenotypes and
  impaired ciliogenesis. Which of these two arms, or what combination of them,
  accounts for the human malformations is not yet settled. Fewer than ten
  affected individuals have been reported worldwide.
disease_term:
  preferred_term: cardiofacioneurodevelopmental syndrome
  term:
    id: MONDO:0030873
    label: cardiofacioneurodevelopmental syndrome
parents:
- Multiple congenital anomaly syndrome
- Orofacial clefting syndrome
- Mendelian neurodevelopmental disorder
- Disorder of clathrin-mediated endocytosis
classifications:
  harrisons_chapter:
  - classification_value: GENETICS_ENVIRONMENT_DISEASE
    evidence:
    - reference: PMID:32307552
      reference_title: Loss of function mutations in CCDC32 cause a congenital syndrome
        characterized by craniofacial, cardiac and neurodevelopmental anomalies.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: Using whole exome sequencing, we identified homozygous frameshift CCDC32
        variants in three affected individuals.
      explanation: >-
        A monogenic recessive malformation syndrome defined and diagnosed by
        exome sequencing belongs to the genetics chapter.
  - classification_value: NEUROLOGIC
    evidence:
    - reference: PMID:41639596
      reference_title: Two siblings with CCDC32-related cardiofacioneurodevelopmental
        syndrome diagnosed by clinical RNA-sequencing and review of literature.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: the clinical phenotype can include microcephaly, facial malformations,
        developmental delay, cerebellar hypoplasia, and cardiac anomalies
      explanation: >-
        Developmental delay, microcephaly and cerebellar hypoplasia place the
        entity in the neurology chapter alongside its malformation features.
  - classification_value: CARDIOVASCULAR
    evidence:
    - reference: PMID:32307552
      reference_title: Loss of function mutations in CCDC32 cause a congenital syndrome
        characterized by craniofacial, cardiac and neurodevelopmental anomalies.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: we investigated the genetic and mechanistic cause of disease in two
        independent consanguineous families affected by overlapping craniofacial,
        cardiac, laterality and neurodevelopmental anomalies
      explanation: >-
        Congenital cardiac and laterality anomalies are part of the defining
        phenotype, so the entry also belongs to the cardiovascular chapter.
notes: >-
  Scope, naming, evidence and provenance notes for this entry.


  (1) NAMED-ENTITY CONFUSION RISK - READ THIS FIRST. "Cardiofacioneurodevelopmental
  syndrome" (CFNDS, MONDO:0030873, OMIM:619123, CCDC32/HGNC:28295) is one letter
  group away from "cardiofaciocutaneous syndrome" (CFC, MONDO:0015280,
  OMIMPS:115150, a RASopathy caused by BRAF, MAP2K1, MAP2K2 and KRAS), which is
  already curated in this repository as `Cardiofaciocutaneous_Syndrome`. The two
  are unrelated in gene, mechanism and management, and both abbreviate to a
  four-letter acronym beginning "CF". Before this entry was written the MONDO
  record was pulled directly (`runoak -i sqlite:obo:mondo info MONDO:0030873 -O
  obo`) and returned `relationship: RO:0004003 HGNC:28295 ! CCDC32` and `xref:
  OMIM:619123`, and `runoak relationships HGNC:28295` returned MONDO:0030873 as
  the only disease linked to CCDC32. Every clinical PMID cited here
  (PMID:32307552, PMID:35451546, PMID:38818818, PMID:41639596) names CCDC32 in
  its title or abstract, and PMID:41639596 states the OMIM number explicitly as
  MIM:619123. No RASopathy gene appears anywhere in this entry except in the
  differential-diagnosis block, where CFC is recorded precisely so that the
  confusion is documented rather than latent.


  (2) HOW THE DEEP-RESEARCH RUN WAS AND WAS NOT USED. `just research-disorder
  claude_code Cardiofacioneurodevelopmental_Syndrome` was run and its output is
  committed at
  `research/Cardiofacioneurodevelopmental_Syndrome-deep-research-claude_code.md`.
  The NEC preflight on that report passed: a case-insensitive gene-mention count
  over the report body returns 123 hits for CCDC32 plus its old symbol C15orf57
  against 3 genuine hits for BRAF, 2 for MAP2K1, 2 for KRAS and 1 for MAP2K2, all
  of which occur inside a differential-diagnosis row for cardiofaciocutaneous
  syndrome. (A naive grep for "braf" also matches 19 occurrences of the substring
  inside "zebrafish" - the raw count is misleading and was inspected in context.)
  The report asserts OMIM:619123 ten times and mentions 115150 once, again only
  in the cardiofaciocutaneous row. Dominant gene and OMIM therefore both match
  MONDO:0030873, so the report is NOT NEC-suspect. Despite that, the entry was
  drafted from primary literature before the report finished, and the report was
  used only (a) as a cross-check on coverage, (b) as the source of the leads in
  notes (10) and (11), each of which was then independently re-verified against
  the primary source named there, and (c) for nothing else. No PMID, snippet or
  ontology identifier in this entry was taken from the report on trust; every one
  was fetched with `just fetch-reference` and checked against the cached body, or
  resolved with `runoak`.


  (3) NO GENEREVIEWS CHAPTER EXISTS FOR THIS DISEASE. PubMed searches run on
  2026-08-01 for "CCDC32[All Fields] AND GeneReviews[All Fields]" and
  "cardiofacioneurodevelopmental syndrome GeneReviews[All Fields]" each returned
  zero records. The mandatory GeneReviews phenotype baseline therefore does not
  apply. NOTE that one GeneReviews chapter IS cited in this entry, PMID:20301365,
  but it is the chapter for cardiofaciocutaneous syndrome and is used ONLY inside
  the differential-diagnosis block; it is not a source for any CFNDS claim. It
  carries a `GeneReviews` tag in the top-level `references:` block because it is
  genuinely a GeneReviews article, which is what that tag records - the tag must
  not be read as meaning that CFNDS has a chapter. The phenotype baseline
  actually used is the 2026 literature review in PMID:41639596, the phenotype
  synthesis in PMID:35451546, and the HPO annotation set described in note (10).


  (4) NO FREQUENCY BANDS ARE ASSERTED ANYWHERE IN THIS ENTRY, AND THAT IS
  DELIBERATE. The total published denominator is fewer than ten individuals.
  PMID:41639596 states that before its own report CFNDS "has only been described
  in four living individuals and one terminated fetus from four families", and
  adds two siblings, which resolves to six living individuals plus one fetus from
  five families. Every per-feature count available is therefore a fraction of a
  single-digit denominator drawn from four separate case reports with
  non-uniform ascertainment and non-uniform investigation (not every patient had
  brain MRI, echocardiography or audiometry reported). Converting, say, "the
  three individuals with CFNDS" into VERY_FREQUENT would present a 3/3 count
  from 2022 as a population band, and the denominator has since grown. Raw counts
  and the paper each came from are recorded in the individual phenotype `notes:`
  instead. `diagnostic: true` is set only on the two features PMID:35451546
  explicitly calls the core phenotype.


  (5) PMID:38818818 HAS NO ABSTRACT IN PUBMED, AND IS CITED ACCORDINGLY. The Clin
  Dysmorphol report of the fourth patient is indexed without an abstract, so the
  cached reference body contains only the bibliographic header. The single
  evidence item that cites it quotes the article TITLE verbatim, and its
  `explanation` says so. The title is a substantive assertion (a novel homozygous
  CCDC32 deletion causing CFNDS in a fourth patient) and no clinical detail from
  that paper is asserted anywhere in this entry, because none is quotable.


  (6) TWO MECHANISM ARMS, BOTH CURATED, NEITHER PRESENTED AS SETTLED. The
  endocytic arm (CCDC32 as an AP-2 assembly chaperone) is now supported by three
  independent structural and cell-biological papers (PMID:39145939,
  PMID:41489497, PMID:42234739) plus the co-essentiality screen that first
  connected the gene to AP2 (PMID:33859415), and is modelled with
  `mechanism_confidence: ESTABLISHED` at the molecular level. The ciliary arm
  rests on the zebrafish and cell-culture data in the original report
  (PMID:32307552), was described by its own authors as "at least partially"
  involved, and has not been independently replicated in the six years since; it
  is modelled with `mechanism_confidence: PROVISIONAL`. Critically, NEITHER arm
  has been shown to produce the human craniofacial, cardiac or brain
  malformations - both edges into the morphogenesis node are
  INDIRECT_UNKNOWN_INTERMEDIATES. See the `mechanistic_hypotheses` block and the
  `ccdc32_ap2_versus_cilia` discussion.


  (7) THE THREE AP-2 MECHANISM PAPERS DISAGREE WITH EACH OTHER ON DETAIL, AND
  THE DISAGREEMENT IS CURATED RATHER THAN SMOOTHED OVER. PMID:39145939 reports
  CCDC32 as a transient assembly chaperone released before AP2 matures, and
  could not detect binding between tagged CCDC32 and the mature complex.
  PMID:41489497 reports the opposite for the mature complex, showing CCDC32
  binding full-length AP2 in cells and being recruited to clathrin-coated pits.
  PMID:42234739 finds that in solution CCDC32 actively disassembles AP-2
  tetramers and that PIP2-containing membrane is what permits assembly to
  complete. All three are cited; the tension is recorded in the
  `ccdc32_ap2_chaperone_mechanism` discussion and is not resolved by this entry.


  (8) NO ORPHANET, CLINGEN OR OMIM STRUCTURED-SOURCE RECORD IS CITED, AND THE
  ABSENCE WAS CHECKED. `grep -il -e CCDC32 -e CFNDS -e cardiofacioneuro
  references_cache/ORPHA_*.md references_cache/CGGV_*.md references_cache/CGDS_*.md`
  returns nothing, while the cache does contain hundreds of ORPHA and CGGV
  records generally, so the absence is specific to this disease rather than a
  missing source. For Orphanet the absence appears to be real rather than a cache
  gap: the MONDO record for MONDO:0030873 carries only MEDGEN, OMIM and UMLS
  xrefs and no `Orphanet:` xref, whereas MONDO:0015280 (cardiofaciocutaneous
  syndrome) does carry `Orphanet:1340`. For ClinGen the record exists upstream
  but is not in the local cache; see note (11). Generating either missing record
  would require bumping a `data/*/MANIFEST.yaml` pin, which the curation PR scope
  check forbids. The OMIM number is nonetheless verified twice over: it is the
  MONDO xref and it is stated in the text of PMID:41639596.


  (10) THE HPO ANNOTATION SET IS RICHER THAN THIS ENTRY, AND THE REASON IS
  QUOTABILITY. The HPO annotation for OMIM:619123 was retrieved directly from
  `https://ontology.jax.org/api/network/annotation/OMIM:619123` on 2026-08-01 and
  contains 25 terms with literal patient-count frequencies, all sourced from
  PMID:32307552. Every one of those counts comes from the FULL TEXT of that
  paper, and its abstract - which is all that `just fetch-reference` could
  retrieve, since both the OUP and the PMC routes returned HTTP 403 - names none
  of them. The retrieved set is: Global developmental delay 2/2, Microcephaly
  2/2, Cleft lip 2/2, Cleft palate 2/2, Protruding ear 2/2, Clinodactyly of the
  5th finger 2/2, Feeding difficulties in infancy 2/2, Congenital onset 2/2,
  Cerebellar vermis hypoplasia 1/1, Cryptorchidism 1/1, Atrioventricular canal
  defect 1/2, Ventricular septal defect 1/2, Pulmonic stenosis 1/2, Asplenia 1/2,
  Abdominal situs inversus 1/2, Hypertelorism 1/2, Hypotelorism 1/2, Upslanted
  palpebral fissure 1/2, Micrognathia 1/2, Brachydactyly 1/2, Camptodactyly 1/2,
  Aplasia/Hypoplasia of the nails 1/2, Abnormal dermatoglyphics 1/2, Kyphosis
  1/2, and Autosomal recessive inheritance. Nine of these were promoted into the
  `phenotypes:` list WITHOUT an evidence item, each carrying a `notes:` naming
  HPOA, the count and the source PMID; the selection rule was "changes management
  or bears on the mechanism", which is why the cardiac lesions, asplenia, situs
  inversus, feeding difficulties, cryptorchidism, cerebellar vermis hypoplasia
  and hypotelorism were promoted and the remaining single-observation dysmorphic
  descriptors (protruding ear, upslanted palpebral fissure, micrognathia,
  brachydactyly, clinodactyly, camptodactyly, nail hypoplasia, abnormal
  dermatoglyphics, kyphosis) were left in this note. These nine are the ONLY
  assertions in the entry without an evidence item, and they are flagged as such
  in every one of their `notes:` fields. HYPERTELORISM AND HYPOTELORISM ARE BOTH
  ANNOTATED AT 1/2, WHICH IS NOT AN ERROR: the two index individuals were
  discordant in opposite directions on the same midline measurement. The
  hypertelorism entry is separately evidenced from PMID:35451546.


  (10a) THREE FURTHER PHENOTYPES ARE DELIBERATELY NOT PROMOTED, AND THE REASON IS
  NOT THAT THEY ARE UNIMPORTANT. The deep-research artifact for this entry lists
  three additional features from the full text of PMID:32307552 that are not in
  HPOA: HP:0012110 Hypoplasia of the pons (fetus A-II-2), HP:0000286 Epicanthus
  (individual B-II-1) and HP:0000752 Hyperactivity (individual B-II-1). All three
  are plausible, and pontine hypoplasia in particular would sit naturally beside
  the already-promoted cerebellar vermis hypoplasia as a second posterior-fossa
  finding. They are not promoted because they fail BOTH routes into this entry.
  (a) They are not in the HPO annotation set, so they cannot be promoted on the
  same provenance as the other nine unevidenced phenotypes: the HPO API
  (https://ontology.jax.org/api/network/annotation/OMIM:619123) was re-queried on
  2026-08-01 and returned exactly the 25 terms listed above; none of the three
  appears. (b) They are not quotable, so they cannot be evidenced: PMID:32307552
  was re-fetched with `just fetch-reference PMID:32307552` on 2026-08-01 and the
  tool reported "Content type: abstract_only", and `grep -ni
  "pons\|pontine\|epicanth\|hyperactiv"` across every cached reference used by
  this entry (PMID_32307552, PMID_35451546, PMID_38818818, PMID_41489497,
  PMID_41639596) returns no clinical hit. Promoting them would therefore mean
  asserting three clinical findings on the deep-research report's word alone,
  which is precisely the failure mode the rest of this entry is built to avoid.
  They are recorded here so that a future curator who obtains the full text can
  promote them immediately, with the HPO identifiers already verified.


  (11) CLINGEN CLASSIFIES THE GENE-DISEASE RELATIONSHIP AS MODERATE, AND THIS WAS
  VERIFIED INDEPENDENTLY OF THE DEEP-RESEARCH REPORT. The ClinGen curation page
  for the gene (https://search.clinicalgenome.org/kb/genes/HGNC:28295) was
  fetched during curation on 2026-08-01 and its gene-validity table reads
  "CCDC32 | cardiofacioneurodevelopmental syndrome MONDO:0030873 | AR | Syndromic
  Disorders GCEP | Moderate". Moderate, not Definitive, is the appropriate
  epistemic level for a five-family disease and is consistent with the caution
  taken throughout this entry. No `CGGV:` evidence item is attached because no
  `references_cache/CGGV_*.md` record for this assertion exists locally and
  generating one would require refreshing `data/clingen/MANIFEST.yaml`, which the
  PR scope check forbids. ClinGen has no dosage-sensitivity curation for CCDC32.


  (12) NO `conforms_to` MODULE DECLARATION IS MADE, AND THAT IS A DECISION RATHER
  THAN AN OVERSIGHT. The nearest existing dismech module,
  `pharyngeal_arch_patterning_serial_homology`, is a conceptual neighbour
  (cranial-neural-crest-derived multi-element craniofacial malformation) but the
  lesion here is a vesicle-trafficking assembly chaperone rather than an
  arch-patterning, ribosome or spliceosome lesion, and the CFNDS malformation
  bundle is not confined to arch derivatives - it includes laterality, cardiac
  septation and posterior-fossa components. Forcing conformance would assert a
  mechanism the literature does not support. `ciliopathy_dysfunction` was also
  considered and rejected: CFNDS lacks every cardinal ciliopathy feature (cystic
  kidney disease, retinal dystrophy, postaxial polydactyly), and the ciliary arm
  here is PROVISIONAL rather than established. The genuinely correct target would
  be a new "AP-2 adaptor assembly / clathrin-mediated endocytosis deficiency"
  module, which would have several worked conformers across the pathway (CCDC32
  in this disease, AP2M1 in MONDO:0032823, and the other AP-2-subunit and AAGAB
  disorders). Creating that module is out of scope for this PR.


  (13) THE TERMINAL "DISRUPTED CRANIOFACIAL, CARDIAC AND NEURAL MORPHOGENESIS"
  NODE IS DELIBERATELY LEFT AS ONE NODE. Splitting it into three organ-specific
  outcome nodes was considered and rejected. Splitting a node is warranted when
  the branches carry different evidence or different upstream mechanisms; here
  they would not. Both inbound edges are INDIRECT_UNKNOWN_INTERMEDIATES, and
  neither the AP-2 arm nor the ciliary arm has been connected to ANY of the three
  organ outcomes specifically - there is no craniofacial-specific edge, no
  cardiac-specific edge and no neural-specific edge to be had, and three copies
  of the same two unresolved edges would assert an organ-level resolution the
  literature does not contain. The per-organ detail that would justify a split is
  already carried at the correct granularity in the `phenotypes:` list, where the
  clefts, the septal defects and the vermis hypoplasia are separate entries with
  their own terms and evidence. Revisit this if a study ever attributes a
  specific organ malformation to a specific arm.


  (9) WHAT IS KNOWINGLY ABSENT. No treatment in this entry is disease-modifying,
  and no treatment carries an evidence item, because none exists: a PubMed search
  on 2026-08-01 for "(cardiofacioneurodevelopmental OR CFNDS) AND (management OR
  treatment OR guideline)" returned one record, on nanodiamond toxicology, which
  is unrelated. The treatments listed are generic supportive measures inferred
  from the phenotype and are labelled as such. No prevalence rate, survival
  figure, genotype-phenotype correlation or recurrence-risk figure beyond the
  standard autosomal recessive 25% is asserted. No mouse model of Ccdc32
  deficiency was located. The zebrafish work is curated under `animal_models` and
  its evidence items are tagged MODEL_ORGANISM so they can never be mistaken for
  human data. Facial dysmorphism is curated only at the level of the two specific
  features that are quotable (hypertelorism, and the orofacial clefts); the
  detailed gestalt described in the individual case reports is not transcribed,
  because those descriptions are in full texts that are not in the reference
  cache.
inheritance:
- name: Autosomal recessive
  description: >-
    CFNDS requires two damaged CCDC32 alleles. Every family reported to date has
    been either consanguineous with a homozygous variant or has carried a
    biallelic deletion; heterozygous parents are unaffected.
  inheritance_term:
    preferred_term: Autosomal recessive inheritance
    term:
      id: HP:0000007
      label: Autosomal recessive inheritance
  evidence:
  - reference: PMID:41639596
    reference_title: Two siblings with CCDC32-related cardiofacioneurodevelopmental
      syndrome diagnosed by clinical RNA-sequencing and review of literature.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: Cardiofacioneurodevelopmental syndrome (CFNDS, MIM:619123) is a rare genetic
      disorder caused by bi-allelic pathogenic variants in CCDC32.
    explanation: >-
      States the biallelic requirement directly, and anchors the OMIM identifier
      used for the NEC check.
  - reference: PMID:32307552
    reference_title: Loss of function mutations in CCDC32 cause a congenital syndrome
      characterized by craniofacial, cardiac and neurodevelopmental anomalies.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: we investigated the genetic and mechanistic cause of disease in two independent
      consanguineous families affected by overlapping craniofacial, cardiac, laterality
      and neurodevelopmental anomalies
    explanation: >-
      The founding report ascertained two consanguineous families, the classic
      setting for a recessive disorder.
prevalence:
- population: Global
  measure_type: CASES_IN_LITERATURE
  prevalence_class: ULTRA_RARE
  notes: >-
    No population prevalence, birth prevalence or carrier frequency has ever
    been published for CFNDS, so the qualitative ULTRA_RARE tier is used and the
    case count is recorded here rather than converted into a rate. As of the 2026
    review, four living individuals and one terminated fetus from four families
    had been described (PMID:41639596); that same paper adds a sibling pair,
    which resolves to six living individuals plus one fetus from five families.
    The reports are PMID:32307552 (two consanguineous families), PMID:35451546
    (a ninth-year-old girl, described by its authors as a novel patient),
    PMID:38818818 (described by its authors as the fourth patient) and
    PMID:41639596 (two siblings).
  evidence:
  - reference: PMID:41639596
    reference_title: Two siblings with CCDC32-related cardiofacioneurodevelopmental
      syndrome diagnosed by clinical RNA-sequencing and review of literature.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: So far, CFNDS has only been described in four living individuals and one
      terminated fetus from four families
    explanation: >-
      Gives the published denominator immediately before this report, which is
      the basis for the ultra-rare tier.
progression:
- age_range: Prenatal to birth
  notes: >-
    The defining lesions are structural malformations that are established during
    embryogenesis and are present at birth: orofacial clefting, congenital
    cardiac anomalies, laterality anomalies and brain malformations. One of the
    reported conceptions was a terminated fetus, so the phenotype can be severe
    enough to be recognised prenatally.
  evidence:
  - reference: PMID:32307552
    reference_title: Loss of function mutations in CCDC32 cause a congenital syndrome
      characterized by craniofacial, cardiac and neurodevelopmental anomalies.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: we investigated the genetic and mechanistic cause of disease in two independent
      consanguineous families affected by overlapping craniofacial, cardiac, laterality
      and neurodevelopmental anomalies
    explanation: >-
      Craniofacial, cardiac and laterality anomalies are congenital structural
      defects, fixing the onset of the malformation component at birth or before.
- age_range: Infancy through childhood
  notes: >-
    The neurodevelopmental component becomes apparent postnatally as
    developmental delay and later intellectual disability, and growth
    impairment or microcephaly may become evident after birth rather than being
    present at delivery. The oldest individual reported in detail was nine years
    old at publication. No natural-history study, and no data on adult outcome or
    life expectancy, has been published.
  evidence:
  - reference: PMID:35451546
    reference_title: "Cardiofacioneurodevelopmental syndrome: Report of a novel patient\
      \ and expansion of the phenotype."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: Variable abnormalities of the face, brain, heart, fingers, and toes and
      postnatal growth retardation or microcephaly can be present.
    explanation: >-
      Identifies growth retardation and microcephaly as postnatal rather than
      necessarily congenital findings.
mechanistic_hypotheses:
- hypothesis_group_id: ccdc32_ap2_endocytic_model
  hypothesis_label: AP-2 Assembly Chaperone / Clathrin-Mediated Endocytosis Model
  status: CANONICAL
  description: >-
    The best-supported model is that CCDC32 is a dedicated assembly factor for the
    AP-2 clathrin adaptor complex, and that loss of CCDC32 causes a cell-wide
    deficit in clathrin-mediated endocytosis which in turn disrupts the
    signalling and receptor-trafficking events on which craniofacial, cardiac and
    neural development depend. The model is supported by an unbiased
    co-essentiality screen that first linked the gene to AP2, by biochemical
    reconstitution of the AAGAB-to-CCDC32 handover that builds AP2, by live-cell
    imaging showing that CCDC32 depletion destabilises clathrin-coated pits, and
    by structural work showing that CCDC32 deletion causes loss of all AP-2
    subunits in vivo. It is further supported by the observation that all the
    disease alleles characterised to date truncate CCDC32 before the alpha-helix
    that mediates AP-2 binding.
  evidence:
  - reference: PMID:39145939
    reference_title: An AAGAB-to-CCDC32 handover mechanism controls the assembly of
      the AP2 adaptor complex.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: We identified CCDC32 as another chaperone regulating AP2 assembly.
    explanation: Establishes the core molecular role of the protein.
  - reference: PMID:39145939
    reference_title: An AAGAB-to-CCDC32 handover mechanism controls the assembly of
      the AP2 adaptor complex.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: The AP2-regulating function of CCDC32 is disrupted by a disease-causing
      mutation.
    explanation: >-
      Directly connects the chaperone function to a disease allele rather than
      leaving the link inferential.
  - reference: PMID:41489497
    reference_title: CCDC32 stabilizes clathrin-coated pits and drives their invagination.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: These findings show that this loss-of-function nonsense mutation in CCDC32
      abolishes its interactions with AP2 and inhibits CME, likely contributing to
      the development of CFNDS.
    explanation: >-
      Tests a patient-derived truncation directly and reports that it abolishes
      AP2 binding and inhibits endocytosis.
- hypothesis_group_id: ccdc32_ciliary_model
  hypothesis_label: Ciliary Contribution Model
  status: ALTERNATIVE
  description: >-
    The original disease report proposed that CFNDS is at least partly a
    ciliopathy. Its authors noted that several patient features overlap defects
    common to ciliopathies, showed that zebrafish ccdc32 depletion recapitulates
    the human phenotypes, and showed that ccdc32 is required for normal cilium
    formation in zebrafish embryos and in mammalian cell culture. The presence of
    laterality anomalies in the original families is the clinical observation that
    most strongly favours a ciliary contribution, since laterality determination
    is a canonical motile-cilium-dependent process.
  notes: >-
    Classified ALTERNATIVE rather than CANONICAL, and carried on a PROVISIONAL
    pathophysiology node, because the finding has not been independently
    replicated since 2020, its own authors phrased the conclusion as ciliary
    defects being "at least partially" involved, and none of the three subsequent
    mechanistic papers on CCDC32 examined cilia at all. The two models are not
    mutually exclusive: AP-2 and clathrin-mediated endocytosis have documented
    roles in ciliary membrane trafficking, so an endocytic primary defect could
    produce a secondary ciliary phenotype.
  evidence:
  - reference: PMID:32307552
    reference_title: Loss of function mutations in CCDC32 cause a congenital syndrome
      characterized by craniofacial, cardiac and neurodevelopmental anomalies.
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: we show that ccdc32 is required for normal cilia formation in zebrafish
      embryos and mammalian cell culture, arguing that ciliary defects are at least
      partially involved in the pathomechanism of this disorder
    explanation: >-
      The single primary source for the ciliary model, stated by its own authors
      as a partial rather than complete explanation.
pathophysiology:
- name: Biallelic CCDC32 Loss of Function
  description: >-
    Homozygous or compound-heterozygous loss-of-function variants in CCDC32
    (also known as C15orf57, at 15q15.1) remove or truncate a small
    185-amino-acid coiled-coil protein. The alleles characterised to date are
    frameshift or nonsense variants that terminate translation after the first
    9, 54 or 80 residues, and whole-gene or multi-exon deletions. All of the
    characterised truncations lie upstream of the alpha-helix formed by residues
    78 to 98, which is the segment required for binding the AP-2 alpha subunit.
  role: root
  biological_scale: MOLECULAR
  mechanism_confidence: ESTABLISHED
  gene:
    preferred_term: CCDC32
    term:
      id: hgnc:28295
      label: CCDC32
  molecular_functions:
  - preferred_term: AP-2 adaptor complex binding
    term:
      id: GO:0035612
      label: AP-2 adaptor complex binding
    modifier: ABSENT
  downstream:
  - target: Failure of AP-2 Adaptor Complex Assembly
    causal_link_type: DIRECT
    description: >-
      CCDC32 is the assembly chaperone that templates AP-2 tetramer formation, so
      its loss is directly a failure of that assembly step.
    evidence:
    - reference: PMID:42234739
      reference_title: CCDC32 collaborates with the membrane to assemble the AP-2 clathrin
        adaptor complex.
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: coiled-coil domain-containing protein 32 (CCDC32), whose deletion causes
        loss of all AP-2 subunits in vivo
      explanation: >-
        Deleting CCDC32 abolishes the assembled complex, which is the causal
        step this edge asserts.
  - target: Defective Ciliogenesis
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: >-
      Depletion of the zebrafish orthologue impairs cilium formation, but no
      molecular route from the CCDC32 defect to the ciliary phenotype has been
      identified, and it is not known whether the ciliary effect is downstream of
      the endocytic one.
    evidence:
    - reference: PMID:32307552
      reference_title: Loss of function mutations in CCDC32 cause a congenital syndrome
        characterized by craniofacial, cardiac and neurodevelopmental anomalies.
      supports: PARTIAL
      evidence_source: MODEL_ORGANISM
      snippet: we show that ccdc32 is required for normal cilia formation in zebrafish
        embryos and mammalian cell culture
      explanation: >-
        Establishes that loss of the gene product impairs ciliogenesis. PARTIAL
        because the experiments do not identify any intermediate step, which is
        why the edge is typed INDIRECT_UNKNOWN_INTERMEDIATES.
  evidence:
  - reference: PMID:32307552
    reference_title: Loss of function mutations in CCDC32 cause a congenital syndrome
      characterized by craniofacial, cardiac and neurodevelopmental anomalies.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: Using whole exome sequencing, we identified homozygous frameshift CCDC32
      variants in three affected individuals.
    explanation: The founding identification of biallelic loss-of-function alleles.
  - reference: PMID:41489497
    reference_title: CCDC32 stabilizes clathrin-coated pits and drives their invagination.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: Clinical genome sequencing of three patients with cardio-facio-neuro-developmental
      syndrome (CFNDS) revealed three homozygous nonsense mutations that only express
      the first 9, 54, and 80 aa of CCDC32, respectively
    explanation: >-
      Specifies the residue positions at which the reported disease alleles
      truncate the protein.
  - reference: PMID:41489497
    reference_title: CCDC32 stabilizes clathrin-coated pits and drives their invagination.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: Deletion of aa78-98 in CCDC32, corresponding to a predicted alpha-helix,
      abrogates AP2 binding
    explanation: >-
      Identifies the protein segment that all reported disease truncations
      remove, explaining why they are loss of function for AP-2 binding.
- name: Failure of AP-2 Adaptor Complex Assembly
  description: >-
    AP-2 is a heterotetramer of alpha, beta2, mu2 and sigma2 subunits and is the
    principal cargo adaptor of clathrin-mediated endocytosis. Its assembly is a
    chaperoned, ordered process: AAGAB first stabilises the alpha and sigma2
    subunits, CCDC32 then displaces AAGAB to form an alpha-sigma2-CCDC32 ternary
    template, and that template sequentially recruits mu2 and beta2 before CCDC32
    is released. Without CCDC32 the handover cannot occur and cells lose AP-2
    complexes.
  biological_scale: MOLECULAR
  mechanism_confidence: ESTABLISHED
  cellular_components:
  - preferred_term: AP-2 adaptor complex
    term:
      id: GO:0030122
      label: AP-2 adaptor complex
  protein_complexes:
  - preferred_term: AP-2 clathrin adaptor complex
    term:
      id: GO:0030122
      label: AP-2 adaptor complex
  downstream:
  - target: Clathrin-Coated Pit Destabilization
    causal_link_type: DIRECT
    description: >-
      AP-2 nucleates and stabilises nascent clathrin-coated pits, so depletion of
      assembled AP-2 is directly a coated-pit stability defect.
    evidence:
    - reference: PMID:41489497
      reference_title: CCDC32 stabilizes clathrin-coated pits and drives their invagination.
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: We show by quantitative live cell imaging that siRNA-mediated knockdown
        of CCDC32, a poorly characterized endocytic accessory protein, leads to the
        accumulation of unstable flat clathrin assemblies.
      explanation: >-
        Losing CCDC32 function produces the coated-pit instability that this
        edge asserts.
  evidence:
  - reference: PMID:39145939
    reference_title: An AAGAB-to-CCDC32 handover mechanism controls the assembly of
      the AP2 adaptor complex.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: These findings demonstrate that AP2 is assembled by a handover mechanism
      switching from AAGAB-based initiation complexes to CCDC32-based template complexes.
    explanation: >-
      A complete sentence stating the ordered, chaperoned nature of AP2 assembly
      and CCDC32's position in it, which is what this edge asserts. This replaces
      an earlier mid-clause fragment ("Here, we found that AAGAB initiates AP2
      assembly by stabilizing its") that had been truncated to avoid quoting the
      Greek-lettered subunit names; the substituted sentence carries the same
      claim, is ASCII throughout, and does not end mid-predicate.
  - reference: PMID:42234739
    reference_title: CCDC32 collaborates with the membrane to assemble the AP-2 clathrin
      adaptor complex.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: coiled-coil domain-containing protein 32 (CCDC32), whose deletion causes
      loss of all AP-2 subunits in vivo
    explanation: >-
      States the consequence of losing CCDC32 for the complex as a whole, which
      is the step this node models.
  - reference: PMID:33859415
    reference_title: A genome-wide atlas of co-essential modules assigns function to
      uncharacterized genes.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: We also show that C15orf57 encodes a protein that binds the AP2 complex,
      localizes to clathrin-coated pits and enables efficient transferrin uptake.
    explanation: >-
      The unbiased co-essentiality screen that first assigned CCDC32 (C15orf57)
      to the AP2 module.
- name: Clathrin-Coated Pit Destabilization
  description: >-
    Loss of CCDC32 function leaves the plasma membrane populated by flat,
    short-lived clathrin assemblies that fail to curve and invaginate. Invagination
    of the nascent coated pit is the checkpoint that determines whether a pit
    matures productively or aborts, so this is the point at which the molecular
    defect becomes a cell-biological one.
  biological_scale: CELLULAR
  mechanism_confidence: ESTABLISHED
  cellular_components:
  - preferred_term: Clathrin-coated pit
    term:
      id: GO:0005905
      label: clathrin-coated pit
  downstream:
  - target: Deficient Clathrin-Mediated Endocytosis
    causal_link_type: DIRECT
    description: >-
      Coated pits that cannot invaginate cannot become coated vesicles, so cargo
      internalisation falls.
    evidence:
    - reference: PMID:41489497
      reference_title: CCDC32 stabilizes clathrin-coated pits and drives their invagination.
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: our data demonstrate the function of a novel endocytic accessory protein,
        CCDC32, in regulating CCP stabilization and invagination, critical early stages
        of CME
      explanation: >-
        States the coupling between coated-pit stabilisation and invagination
        and the endocytic pathway as a whole.
  evidence:
  - reference: PMID:41489497
    reference_title: CCDC32 stabilizes clathrin-coated pits and drives their invagination.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: We show by quantitative live cell imaging that siRNA-mediated knockdown
      of CCDC32, a poorly characterized endocytic accessory protein, leads to the accumulation
      of unstable flat clathrin assemblies.
    explanation: >-
      Direct live-cell demonstration of the coated-pit phenotype caused by loss
      of CCDC32.
- name: Deficient Clathrin-Mediated Endocytosis
  description: >-
    The functional read-out of the coated-pit defect is reduced receptor-mediated
    internalisation, measured in the primary literature as impaired transferrin
    receptor uptake. Clathrin-mediated endocytosis controls the surface residence
    and signalling output of most developmental receptors, and its failure is the
    proposed bridge between the molecular lesion and the malformation phenotype.
  biological_scale: CELLULAR
  mechanism_confidence: ESTABLISHED
  biological_processes:
  - preferred_term: Clathrin-dependent endocytosis
    term:
      id: GO:0072583
      label: clathrin-dependent endocytosis
    modifier: DECREASED
  downstream:
  - target: Disrupted Craniofacial, Cardiac and Neural Morphogenesis
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: >-
      No specific receptor, signalling pathway or cell population has been shown
      to link the endocytic deficit to the human malformations. The supporting
      argument is comparative: mice lacking individual AP2 subunits develop cleft
      palate and cardiac defects, and the clinical features of CCDC32 loss
      resemble those of AP2 loss-of-function mutations.
    evidence:
    - reference: PMID:41489497
      reference_title: CCDC32 stabilizes clathrin-coated pits and drives their invagination.
      supports: PARTIAL
      evidence_source: IN_VITRO
      snippet: it is interesting that the clinical features of CCDC32 loss-of-function
        are similar to those resulting from AP2 loss-of-function mutations
      explanation: >-
        The comparative argument that the endocytic lesion explains the clinical
        picture. PARTIAL because resemblance between two disease phenotypes is
        an analogy, not a demonstrated causal chain, which is why this edge is
        typed INDIRECT_UNKNOWN_INTERMEDIATES.
  evidence:
  - reference: PMID:33859415
    reference_title: A genome-wide atlas of co-essential modules assigns function to
      uncharacterized genes.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: We also show that C15orf57 encodes a protein that binds the AP2 complex,
      localizes to clathrin-coated pits and enables efficient transferrin uptake.
    explanation: >-
      Establishes that CCDC32 is required for efficient receptor-mediated
      internalisation, the functional read-out modelled by this node.
  - reference: PMID:35451546
    reference_title: "Cardiofacioneurodevelopmental syndrome: Report of a novel patient\
      \ and expansion of the phenotype."
    supports: PARTIAL
    evidence_source: MODEL_ORGANISM
    snippet: Cleft palate and cardiac defects observed in mice deficient of different
      AP2 subunits support a CCDC32 function in the AP2 complex.
    explanation: >-
      The comparative argument that links AP2 dysfunction to the CFNDS
      malformation pattern. Marked PARTIAL and MODEL_ORGANISM because it is a
      secondhand report of mouse data inside a human case report, and because the
      mice are AP2-subunit mutants rather than Ccdc32 mutants.
- name: Defective Ciliogenesis
  description: >-
    An alternative, and possibly parallel, arm of the pathomechanism. Depletion of
    ccdc32 in zebrafish embryos and in mammalian cell culture impairs cilium
    formation. Because primary and motile cilia govern Hedgehog signalling,
    left-right patterning and craniofacial neural-crest development, a ciliary
    defect would account for the laterality anomalies and for the overlap of the
    CFNDS phenotype with recognised ciliopathies.
  biological_scale: CELLULAR
  mechanism_confidence: PROVISIONAL
  biological_processes:
  - preferred_term: Cilium assembly
    term:
      id: GO:0060271
      label: cilium assembly
    modifier: DECREASED
  notes: >-
    PROVISIONAL, not ESTABLISHED. The evidence is a single 2020 paper, has not
    been independently replicated, and the three subsequent mechanistic studies of
    CCDC32 did not examine cilia. It is also unresolved whether any ciliary
    phenotype is a primary function of CCDC32 or a secondary consequence of
    impaired clathrin-mediated endocytosis, which is itself required for ciliary
    membrane trafficking.
  downstream:
  - target: Disrupted Craniofacial, Cardiac and Neural Morphogenesis
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: >-
      Ciliary signalling defects are a recognised route to craniofacial, cardiac
      and laterality malformations, but this route has not been demonstrated for
      CCDC32 in human tissue.
    evidence:
    - reference: PMID:32307552
      reference_title: Loss of function mutations in CCDC32 cause a congenital syndrome
        characterized by craniofacial, cardiac and neurodevelopmental anomalies.
      supports: PARTIAL
      evidence_source: MODEL_ORGANISM
      snippet: arguing that ciliary defects are at least partially involved in the
        pathomechanism of this disorder
      explanation: >-
        The authors own statement of the edge, quoted with their hedge intact.
        PARTIAL because "at least partially" is exactly the uncertainty this
        edge type encodes.
  evidence:
  - reference: PMID:32307552
    reference_title: Loss of function mutations in CCDC32 cause a congenital syndrome
      characterized by craniofacial, cardiac and neurodevelopmental anomalies.
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: we show that ccdc32 is required for normal cilia formation in zebrafish
      embryos and mammalian cell culture, arguing that ciliary defects are at least
      partially involved in the pathomechanism of this disorder
    explanation: >-
      The sole primary evidence for the ciliary arm, quoted with the authors own
      hedge intact.
  - reference: PMID:32307552
    reference_title: Loss of function mutations in CCDC32 cause a congenital syndrome
      characterized by craniofacial, cardiac and neurodevelopmental anomalies.
    supports: PARTIAL
    evidence_source: HUMAN_CLINICAL
    snippet: Because some of the patient phenotypes overlap defects common to ciliopathies,
      we asked if loss of CCDC32 might contribute to the dysfunction of this organelle.
    explanation: >-
      Records the clinical observation that motivated the ciliary hypothesis.
      PARTIAL because phenotypic overlap is suggestive, not demonstrative.
- name: Disrupted Craniofacial, Cardiac and Neural Morphogenesis
  description: >-
    The convergent developmental outcome. Failure of the endocytic and possibly
    ciliary machinery during embryogenesis produces the syndrome: failure of
    fusion of the facial prominences giving bilateral cleft lip and palate,
    congenital cardiac malformation, disturbed left-right patterning, and
    maldevelopment of midline and posterior-fossa brain structures giving
    corpus-callosum hypoplasia and cerebellar hypoplasia.
  role: outcome
  biological_scale: ORGANISM
  mechanism_confidence: ESTABLISHED
  biological_processes:
  - preferred_term: Determination of left/right symmetry
    term:
      id: GO:0007368
      label: determination of left/right symmetry
    modifier: ABNORMAL
  evidence:
  - reference: PMID:35451546
    reference_title: "Cardiofacioneurodevelopmental syndrome: Report of a novel patient\
      \ and expansion of the phenotype."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: The cardiofacioneurodevelopmental syndrome (CFNDS) is characterized by
      craniofacial anomalies including bilateral cleft lip and palate, cardiac, skeletal,
      and neurodevelopmental features and additional variable manifestations.
    explanation: >-
      Defines the multi-system malformation outcome that this terminal node
      represents.
  - reference: PMID:32307552
    reference_title: Loss of function mutations in CCDC32 cause a congenital syndrome
      characterized by craniofacial, cardiac and neurodevelopmental anomalies.
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: Functional analysis in a zebrafish model revealed that ccdc32 depletion
      recapitulates the human phenotypes.
    explanation: >-
      Shows that depleting the orthologue in a vertebrate embryo reproduces the
      multi-system malformation pattern.
phenotypes:
- name: Cleft lip
  category: Head and Neck
  description: >-
    Bilateral cleft lip, occurring together with cleft palate, is one of the two
    features that PMID:35451546 designated as the core phenotype of CFNDS.
  diagnostic: true
  notes: >-
    Reported in all three individuals known at the time of PMID:35451546, and
    named as part of the disease definition in that paper. No frequency band is
    asserted: see entry note (4).
  phenotype_term:
    preferred_term: Bilateral cleft lip
    term:
      id: HP:0410030
      label: Cleft lip
    onset:
      onset_category: CONGENITAL
  evidence:
  - reference: PMID:35451546
    reference_title: "Cardiofacioneurodevelopmental syndrome: Report of a novel patient\
      \ and expansion of the phenotype."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: We describe a core phenotype comprising developmental delay and bilateral
      cleft lip and palate in the three individuals with CFNDS.
    explanation: >-
      Designates bilateral cleft lip and palate as one of the two core features
      of the syndrome.
  - reference: PMID:35451546
    reference_title: "Cardiofacioneurodevelopmental syndrome: Report of a novel patient\
      \ and expansion of the phenotype."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: The patient had intellectual disability, marked hypertelorism, bilateral
      cleft lip and palate, and short stature.
    explanation: Documents the finding in the individually reported patient.
- name: Cleft palate
  category: Head and Neck
  description: >-
    Cleft palate accompanies the cleft lip in the reported individuals and is the
    second half of the core craniofacial feature of CFNDS. It is also the
    craniofacial defect seen in mice deficient in AP2 subunits, which is the
    comparative argument linking the human clefting to the AP-2 mechanism.
  diagnostic: true
  notes: >-
    Reported in all three individuals known at the time of PMID:35451546. No
    frequency band is asserted: see entry note (4).
  phenotype_term:
    preferred_term: Bilateral cleft palate
    term:
      id: HP:0000175
      label: Cleft palate
    onset:
      onset_category: CONGENITAL
  evidence:
  - reference: PMID:35451546
    reference_title: "Cardiofacioneurodevelopmental syndrome: Report of a novel patient\
      \ and expansion of the phenotype."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: The cardiofacioneurodevelopmental syndrome (CFNDS) is characterized by
      craniofacial anomalies including bilateral cleft lip and palate, cardiac, skeletal,
      and neurodevelopmental features and additional variable manifestations.
    explanation: Names bilateral cleft lip and palate as the defining craniofacial anomaly.
- name: Global developmental delay
  category: Nervous System
  description: >-
    Developmental delay is the second component of the core phenotype and is
    present in every reported individual with sufficient postnatal follow-up.
  diagnostic: true
  notes: >-
    Named as core in PMID:35451546 across the three individuals then known, and
    listed again among the recurring features in the 2026 review. No frequency
    band is asserted: see entry note (4).
  phenotype_term:
    preferred_term: Global developmental delay
    term:
      id: HP:0001263
      label: Global developmental delay
  evidence:
  - reference: PMID:35451546
    reference_title: "Cardiofacioneurodevelopmental syndrome: Report of a novel patient\
      \ and expansion of the phenotype."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: We describe a core phenotype comprising developmental delay and bilateral
      cleft lip and palate in the three individuals with CFNDS.
    explanation: Designates developmental delay as one of the two core features.
  - reference: PMID:41639596
    reference_title: Two siblings with CCDC32-related cardiofacioneurodevelopmental
      syndrome diagnosed by clinical RNA-sequencing and review of literature.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: the clinical phenotype can include microcephaly, facial malformations,
      developmental delay, cerebellar hypoplasia, and cardiac anomalies
    explanation: The 2026 review carries developmental delay forward as a recurring feature.
- name: Intellectual disability
  category: Nervous System
  description: >-
    The developmental delay evolves into intellectual disability. It was
    documented explicitly in the patient reported in PMID:35451546, who was nine
    years old at the time of publication.
  notes: >-
    Documented in one individually described patient. Because the syndrome is
    congenital and the reported cohort is largely young, the proportion of
    affected individuals old enough for a formal cognitive assessment is small,
    which is a further reason no frequency band is asserted.
  phenotype_term:
    preferred_term: Intellectual disability
    term:
      id: HP:0001249
      label: Intellectual disability
  evidence:
  - reference: PMID:35451546
    reference_title: "Cardiofacioneurodevelopmental syndrome: Report of a novel patient\
      \ and expansion of the phenotype."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: The patient had intellectual disability, marked hypertelorism, bilateral
      cleft lip and palate, and short stature.
    explanation: Direct documentation of intellectual disability in a genotyped patient.
- name: Hypertelorism
  category: Head and Neck
  description: >-
    Marked hypertelorism was a striking feature of the patient reported in
    PMID:35451546 and is the one specific facial measurement, beyond the
    orofacial clefts, that is documented in a quotable source.
  notes: >-
    Interorbital distance is DISCORDANT across the reported individuals. The HPO
    annotation for OMIM:619123 records Hypertelorism at 1/2 AND Hypotelorism at
    1/2 from the same two-patient source, meaning the two index individuals
    deviated in opposite directions on the same measurement, and PMID:35451546
    then reported marked hypertelorism in a third, unrelated patient. Both
    directions are curated as separate phenotypes rather than being merged. This
    entry does not claim a direction is typical.
  phenotype_term:
    preferred_term: Hypertelorism
    term:
      id: HP:0000316
      label: Hypertelorism
    severity: SEVERE
  evidence:
  - reference: PMID:35451546
    reference_title: "Cardiofacioneurodevelopmental syndrome: Report of a novel patient\
      \ and expansion of the phenotype."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: The patient had intellectual disability, marked hypertelorism, bilateral
      cleft lip and palate, and short stature.
    explanation: >-
      Documents hypertelorism, and its severity qualifier, in a genotyped
      patient.
- name: Hypotelorism
  category: Head and Neck
  description: >-
    Hypotelorism was present in one of the two index individuals, while the other
    had hypertelorism. The two opposite deviations of the same midline
    measurement within a two-patient series are recorded separately rather than
    collapsed into a single "abnormal interorbital distance" statement, because
    the discordance is itself the observation.
  notes: >-
    NO EVIDENCE ITEM. Sourced from the HPO annotation for OMIM:619123 retrieved
    on 2026-08-01, which records Hypotelorism at 1/2 with source PMID:32307552.
    The count is derived from the full text of that paper, whose abstract is the
    only part available in the reference cache and which does not mention
    interorbital distance. See entry note (10).
  phenotype_term:
    preferred_term: Hypotelorism
    term:
      id: HP:0000601
      label: Hypotelorism
- name: Atrioventricular canal defect
  category: Cardiovascular
  description: >-
    A complete atrioventricular septal defect was present in one of the two index
    individuals. This is the most surgically consequential cardiac lesion
    reported in the syndrome and is also the lesion classically associated with
    heterotaxy.
  notes: >-
    NO EVIDENCE ITEM. Sourced from the HPO annotation for OMIM:619123 retrieved
    on 2026-08-01, which records Atrioventricular canal defect at 1/2 with source
    PMID:32307552, from that paper's full text. See entry note (10).
  phenotype_term:
    preferred_term: Atrioventricular canal defect
    term:
      id: HP:0006695
      label: Atrioventricular canal defect
    onset:
      onset_category: CONGENITAL
- name: Ventricular septal defect
  category: Cardiovascular
  description: >-
    A ventricular septal defect was present in one of the two index individuals,
    making septation failure part of the reported cardiac spectrum.
  notes: >-
    NO EVIDENCE ITEM. Sourced from the HPO annotation for OMIM:619123 retrieved
    on 2026-08-01, which records Ventricular septal defect at 1/2 with source
    PMID:32307552, from that paper's full text. See entry note (10).
  phenotype_term:
    preferred_term: Ventricular septal defect
    term:
      id: HP:0001629
      label: Ventricular septal defect
    onset:
      onset_category: CONGENITAL
- name: Pulmonic stenosis
  category: Cardiovascular
  description: >-
    Pulmonary valve stenosis was present in one of the two index individuals,
    adding an outflow-tract lesion to the septation defects.
  notes: >-
    NO EVIDENCE ITEM. Sourced from the HPO annotation for OMIM:619123 retrieved
    on 2026-08-01, which records Pulmonic stenosis at 1/2 with source
    PMID:32307552, from that paper's full text. See entry note (10).
  phenotype_term:
    preferred_term: Pulmonic stenosis
    term:
      id: HP:0001642
      label: Pulmonic stenosis
    onset:
      onset_category: CONGENITAL
- name: Asplenia
  category: Cardiovascular
  description: >-
    Absence of the spleen was reported in one of the two index individuals. This
    is the single most clinically urgent finding in the syndrome, because
    functional asplenia confers lifelong susceptibility to invasive infection
    with encapsulated organisms and mandates antibiotic prophylaxis and an
    asplenia immunisation schedule. It also belongs to the laterality complex,
    since asplenia is a cardinal component of right isomerism.
  notes: >-
    NO EVIDENCE ITEM. Sourced from the HPO annotation for OMIM:619123 retrieved
    on 2026-08-01, which records Asplenia at 1/2 with source PMID:32307552, from
    that paper's full text. See entry note (10). Despite the lack of a quotable
    snippet this finding is promoted into the structured phenotype list because
    it directly changes management; the corresponding treatment entry is
    Antimicrobial prophylaxis and immunisation for asplenia.
  phenotype_term:
    preferred_term: Asplenia
    term:
      id: HP:0001746
      label: Asplenia
    onset:
      onset_category: CONGENITAL
- name: Abdominal situs inversus
  category: Prenatal and Birth
  description: >-
    Abdominal situs inversus was present in one of the two index individuals and
    is the specific laterality anomaly behind the general "laterality anomalies"
    phrase in the abstract of the founding report.
  notes: >-
    NO EVIDENCE ITEM. Sourced from the HPO annotation for OMIM:619123 retrieved
    on 2026-08-01, which records Abdominal situs inversus at 1/2 with source
    PMID:32307552, from that paper's full text. See entry note (10). The general
    laterality claim IS separately evidenced, on the Laterality anomaly
    phenotype.
  phenotype_term:
    preferred_term: Abdominal situs inversus
    term:
      id: HP:0003363
      label: Abdominal situs inversus
    onset:
      onset_category: CONGENITAL
- name: Cerebellar vermis hypoplasia
  category: Nervous System
  description: >-
    Vermian hypoplasia was documented in the affected fetus of the founding
    report. It is the anatomically specific counterpart of the general cerebellar
    hypoplasia recorded from the 2026 review, and its presence in a fetus
    establishes that the posterior-fossa anomaly is developmental and prenatal
    rather than acquired.
  notes: >-
    NO EVIDENCE ITEM. Sourced from the HPO annotation for OMIM:619123 retrieved
    on 2026-08-01, which records Cerebellar vermis hypoplasia at 1/1 with source
    PMID:32307552, from that paper's full text. The 1/1 rather than 1/2
    denominator reflects that only one individual had the relevant imaging. See
    entry note (10). The broader Cerebellar hypoplasia phenotype in this entry IS
    separately evidenced from PMID:41639596.
  phenotype_term:
    preferred_term: Cerebellar vermis hypoplasia
    term:
      id: HP:0001320
      label: Cerebellar vermis hypoplasia
- name: Feeding difficulties in infancy
  category: Digestive
  description: >-
    Feeding difficulty in infancy was present in both index individuals. It is
    the expected early consequence of bilateral cleft lip and palate and is the
    first practical management problem the syndrome presents.
  notes: >-
    NO EVIDENCE ITEM. Sourced from the HPO annotation for OMIM:619123 retrieved
    on 2026-08-01, which records Feeding difficulties in infancy at 2/2 with
    source PMID:32307552, from that paper's full text. See entry note (10).
  phenotype_term:
    preferred_term: Feeding difficulties in infancy
    term:
      id: HP:0008872
      label: Feeding difficulties in infancy
    onset:
      onset_category: INFANTILE
- name: Cryptorchidism
  category: Genitourinary
  description: >-
    Undescended testes were reported in the one male individual for whom the
    finding was recorded. It is included because it is surgically actionable.
  notes: >-
    NO EVIDENCE ITEM. Sourced from the HPO annotation for OMIM:619123 retrieved
    on 2026-08-01, which records Cryptorchidism at 1/1 with source PMID:32307552,
    from that paper's full text. The 1/1 denominator is the number of individuals
    in whom the sex-limited finding could be assessed. See entry note (10).
  phenotype_term:
    preferred_term: Cryptorchidism
    term:
      id: HP:0000028
      label: Cryptorchidism
- name: Abnormal facial shape
  category: Head and Neck
  description: >-
    Beyond the clefts and hypertelorism, the reported individuals share variable
    facial malformations. The individual dysmorphic descriptors are given in the
    full texts of the case reports rather than in their abstracts, so only the
    general finding is curated here.
  phenotype_term:
    preferred_term: Facial malformation
    term:
      id: HP:0001999
      label: Abnormal facial shape
  evidence:
  - reference: PMID:41639596
    reference_title: Two siblings with CCDC32-related cardiofacioneurodevelopmental
      syndrome diagnosed by clinical RNA-sequencing and review of literature.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: the clinical phenotype can include microcephaly, facial malformations,
      developmental delay, cerebellar hypoplasia, and cardiac anomalies
    explanation: Lists facial malformations among the recurring features of the syndrome.
  - reference: PMID:35451546
    reference_title: "Cardiofacioneurodevelopmental syndrome: Report of a novel patient\
      \ and expansion of the phenotype."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: Variable abnormalities of the face, brain, heart, fingers, and toes and
      postnatal growth retardation or microcephaly can be present.
    explanation: Records facial abnormality as a variable, non-obligate feature.
- name: Congenital cardiac anomaly
  category: Cardiovascular
  description: >-
    Cardiac malformation is one of the three organ systems named in the disease
    label and was present in the original consanguineous families. The specific
    lesions are described in the case-report full texts rather than in quotable
    abstracts, so the finding is curated at the level of abnormal heart
    morphology rather than as a named defect.
  notes: >-
    Named in the original report and carried forward by the 2026 review. Not
    every reported individual is documented as having had echocardiography, which
    is one reason no frequency band is asserted: see entry note (4).
  phenotype_term:
    preferred_term: Congenital cardiac anomaly
    term:
      id: HP:0001627
      label: Abnormal heart morphology
    onset:
      onset_category: CONGENITAL
  evidence:
  - reference: PMID:32307552
    reference_title: Loss of function mutations in CCDC32 cause a congenital syndrome
      characterized by craniofacial, cardiac and neurodevelopmental anomalies.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: we investigated the genetic and mechanistic cause of disease in two independent
      consanguineous families affected by overlapping craniofacial, cardiac, laterality
      and neurodevelopmental anomalies
    explanation: Documents cardiac anomalies in the founding families.
  - reference: PMID:41639596
    reference_title: Two siblings with CCDC32-related cardiofacioneurodevelopmental
      syndrome diagnosed by clinical RNA-sequencing and review of literature.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: the clinical phenotype can include microcephaly, facial malformations,
      developmental delay, cerebellar hypoplasia, and cardiac anomalies
    explanation: The 2026 review confirms cardiac anomalies as a recurring feature.
- name: Laterality anomaly
  category: Prenatal and Birth
  description: >-
    Laterality (left-right patterning) anomalies were present in the two
    consanguineous families of the founding report. This is the clinical finding
    that most directly motivates the ciliary arm of the pathomechanism, since
    left-right axis determination depends on motile cilia at the embryonic
    organiser.
  notes: >-
    Reported only by PMID:32307552 and not restated in the abstracts of the
    subsequent case reports or of the 2026 review, so it may be a feature of the
    original families rather than a consistent feature of the syndrome.
  phenotype_term:
    preferred_term: Laterality anomaly
    term:
      id: HP:0030853
      label: Heterotaxy
  evidence:
  - reference: PMID:32307552
    reference_title: Loss of function mutations in CCDC32 cause a congenital syndrome
      characterized by craniofacial, cardiac and neurodevelopmental anomalies.
    supports: PARTIAL
    evidence_source: HUMAN_CLINICAL
    snippet: we investigated the genetic and mechanistic cause of disease in two independent
      consanguineous families affected by overlapping craniofacial, cardiac, laterality
      and neurodevelopmental anomalies
    explanation: >-
      Documents laterality anomalies in the founding families. Marked PARTIAL
      because the abstract names the category without specifying whether the
      finding was situs inversus, situs ambiguus or an isolated visceral
      discordance, so the binding to the general heterotaxy term is the closest
      honest fit rather than an exact match.
- name: Hypoplasia of the corpus callosum
  category: Nervous System
  description: >-
    A hypoplastic corpus callosum was demonstrated on brain imaging in the
    patient reported in PMID:35451546, and abnormalities of the brain are listed
    among the variable features of the syndrome.
  phenotype_term:
    preferred_term: Hypoplastic corpus callosum
    term:
      id: HP:0002079
      label: Hypoplasia of the corpus callosum
  evidence:
  - reference: PMID:35451546
    reference_title: "Cardiofacioneurodevelopmental syndrome: Report of a novel patient\
      \ and expansion of the phenotype."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: Brain imaging disclosed hypoplastic corpus callosum.
    explanation: Direct imaging documentation in a genotyped patient.
- name: Cerebellar hypoplasia
  category: Nervous System
  description: >-
    Cerebellar hypoplasia is listed among the recurring features of CFNDS in the
    2026 literature review, extending the brain phenotype beyond the midline
    callosal anomaly to the posterior fossa.
  phenotype_term:
    preferred_term: Cerebellar hypoplasia
    term:
      id: HP:0001321
      label: Cerebellar hypoplasia
  evidence:
  - reference: PMID:41639596
    reference_title: Two siblings with CCDC32-related cardiofacioneurodevelopmental
      syndrome diagnosed by clinical RNA-sequencing and review of literature.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: the clinical phenotype can include microcephaly, facial malformations,
      developmental delay, cerebellar hypoplasia, and cardiac anomalies
    explanation: >-
      The review that pooled the published cases lists cerebellar hypoplasia as
      part of the phenotype.
- name: Microcephaly
  category: Head and Neck
  description: >-
    Microcephaly is a variable feature. PMID:35451546 groups it with postnatal
    growth retardation as an alternative rather than an obligate finding, and the
    2026 review lists it among the recurring features.
  phenotype_term:
    preferred_term: Microcephaly
    term:
      id: HP:0000252
      label: Microcephaly
  evidence:
  - reference: PMID:41639596
    reference_title: Two siblings with CCDC32-related cardiofacioneurodevelopmental
      syndrome diagnosed by clinical RNA-sequencing and review of literature.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: the clinical phenotype can include microcephaly, facial malformations,
      developmental delay, cerebellar hypoplasia, and cardiac anomalies
    explanation: Lists microcephaly among the recurring features.
  - reference: PMID:35451546
    reference_title: "Cardiofacioneurodevelopmental syndrome: Report of a novel patient\
      \ and expansion of the phenotype."
    supports: PARTIAL
    evidence_source: HUMAN_CLINICAL
    snippet: Variable abnormalities of the face, brain, heart, fingers, and toes and
      postnatal growth retardation or microcephaly can be present.
    explanation: >-
      Marked PARTIAL because this sentence presents microcephaly as one of two
      alternative growth-related findings rather than asserting it in any
      specific patient.
- name: Postnatal growth retardation
  category: Growth
  description: >-
    Postnatal growth impairment is a variable feature and is presented in
    PMID:35451546 as an alternative to microcephaly. Short stature was documented
    in the individually reported patient.
  phenotype_term:
    preferred_term: Postnatal growth retardation
    term:
      id: HP:0008897
      label: Postnatal growth retardation
  evidence:
  - reference: PMID:35451546
    reference_title: "Cardiofacioneurodevelopmental syndrome: Report of a novel patient\
      \ and expansion of the phenotype."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: Variable abnormalities of the face, brain, heart, fingers, and toes and
      postnatal growth retardation or microcephaly can be present.
    explanation: Names postnatal growth retardation as a variable feature.
- name: Short stature
  category: Growth
  description: >-
    Short stature was documented in the nine-year-old patient reported in
    PMID:35451546.
  phenotype_term:
    preferred_term: Short stature
    term:
      id: HP:0004322
      label: Short stature
  evidence:
  - reference: PMID:35451546
    reference_title: "Cardiofacioneurodevelopmental syndrome: Report of a novel patient\
      \ and expansion of the phenotype."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: The patient had intellectual disability, marked hypertelorism, bilateral
      cleft lip and palate, and short stature.
    explanation: Direct documentation in a genotyped patient.
- name: Conductive hearing impairment
  category: Ear
  description: >-
    Bilateral conductive hearing loss was documented in the patient reported in
    PMID:35451546. Conductive rather than sensorineural loss is expected in a
    child with bilateral cleft lip and palate, in whom eustachian-tube
    dysfunction and middle-ear effusion are common, so this finding may be a
    consequence of the clefting rather than an independent manifestation.
  phenotype_term:
    preferred_term: Bilateral conductive hearing impairment
    term:
      id: HP:0000405
      label: Conductive hearing impairment
  evidence:
  - reference: PMID:35451546
    reference_title: "Cardiofacioneurodevelopmental syndrome: Report of a novel patient\
      \ and expansion of the phenotype."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: She had bilateral conductive hearing loss, small hands and feet, and finger
      abnormalities.
    explanation: Direct documentation in a genotyped patient.
- name: Small hand
  category: Limbs
  description: >-
    Small hands were documented in the patient reported in PMID:35451546, and
    abnormalities of the fingers and toes are listed among the variable features
    of the syndrome.
  phenotype_term:
    preferred_term: Small hand
    term:
      id: HP:0200055
      label: Small hand
  evidence:
  - reference: PMID:35451546
    reference_title: "Cardiofacioneurodevelopmental syndrome: Report of a novel patient\
      \ and expansion of the phenotype."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: She had bilateral conductive hearing loss, small hands and feet, and finger
      abnormalities.
    explanation: Direct documentation in a genotyped patient.
- name: Short foot
  category: Limbs
  description: >-
    Small feet were documented alongside small hands in the patient reported in
    PMID:35451546.
  phenotype_term:
    preferred_term: Small feet
    term:
      id: HP:0001773
      label: Short foot
  evidence:
  - reference: PMID:35451546
    reference_title: "Cardiofacioneurodevelopmental syndrome: Report of a novel patient\
      \ and expansion of the phenotype."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: She had bilateral conductive hearing loss, small hands and feet, and finger
      abnormalities.
    explanation: Direct documentation in a genotyped patient.
- name: Abnormal finger morphology
  category: Limbs
  description: >-
    Finger abnormalities were documented in the patient reported in PMID:35451546
    and abnormalities of the fingers and toes are named among the variable
    features of the syndrome. The specific digital anomalies are described in the
    case-report full texts, which are not in the reference cache, so the finding
    is curated at the general level.
  phenotype_term:
    preferred_term: Finger abnormalities
    term:
      id: HP:0001167
      label: Abnormal finger morphology
  evidence:
  - reference: PMID:35451546
    reference_title: "Cardiofacioneurodevelopmental syndrome: Report of a novel patient\
      \ and expansion of the phenotype."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: She had bilateral conductive hearing loss, small hands and feet, and finger
      abnormalities.
    explanation: Direct documentation in a genotyped patient.
  - reference: PMID:35451546
    reference_title: "Cardiofacioneurodevelopmental syndrome: Report of a novel patient\
      \ and expansion of the phenotype."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: Variable abnormalities of the face, brain, heart, fingers, and toes and
      postnatal growth retardation or microcephaly can be present.
    explanation: Records digital anomalies as a variable feature of the syndrome.
genetic:
- name: CCDC32
  gene_term:
    preferred_term: CCDC32
    term:
      id: hgnc:28295
      label: CCDC32
  relationship_type: CAUSATIVE
  variant_origin: GERMLINE
  presence: Biallelic loss-of-function variants
  notes: >-
    CCDC32 (HGNC:28295) lies at 15q15.1 and was previously designated C15orf57;
    the older symbol is still used in some of the mechanistic literature and in
    PMID:33859415, and searching only for the current symbol will miss that
    paper. The gene encodes a 185-amino-acid coiled-coil protein. It is the only
    gene linked to this disease in MONDO: `runoak -i sqlite:obo:mondo
    relationships HGNC:28295` returns MONDO:0030873 as the sole disease
    relationship. No genotype-phenotype correlation has been proposed, and with
    fewer than ten reported individuals none could be established.


    TRANSCRIPT-VERSION HAZARD - READ BEFORE COMPARING HGVS STRINGS. The two
    founding frameshift alleles are published in PMID:32307552 as
    NM_001080791.2:c.54dupT p.(Thr19Tyrfs*12) and NM_001080791.2:c.189_190dupGG
    p.(Glu64Glyfs*12), but every CURRENT RefSeq transcript for CCDC32 numbers the
    same two alleles 27 nucleotides (9 codons) lower, as c.27dup p.Thr10fs and
    c.162_163dup p.Glu55fs. This is a transcript-VERSION difference, not a
    transcript-CHOICE difference: the ClinVar records for these alleles
    (VCV000988600.1 and VCV000988601.1, retrieved from the NCBI eutils ClinVar
    esummary and VCV efetch endpoints on 2026-08-01) list c.27dup and
    c.162_163dup identically on NM_001080791.4, NM_001080792.4 (MANE Select),
    NM_052849.5 and ten further variants, so no currently distributed transcript
    reproduces the published numbering. The 9-residue offset is the same one that
    explains the 194-versus-185-amino-acid protein-length discrepancy in the
    literature, and PMID:41489497 documents it directly (see the evidence item on
    the Family B variant below). A search for the published `c.54dupT` string
    will therefore return nothing in ClinVar; search the ClinVar or dbSNP
    identifier instead.


    GENE-LEVEL CONSTRAINT. gnomAD GRCh38 constraint for CCDC32
    (ENSG00000128891), retrieved from the gnomAD GraphQL API
    (https://gnomad.broadinstitute.org/api) on 2026-08-01, is pLI = 0.16 and
    LOEUF (`oe_lof_upper`) = 0.78, from 9 observed against 20.1 expected
    loss-of-function alleles. Both values indicate the gene is TOLERANT of
    heterozygous loss of function - the expected signature for a recessive
    disease gene, and consistent with the unaffected heterozygous parents and
    sibs reported in every family. LOEUF 0.78 sits well above the conventional
    <0.6 threshold used to flag dominant-acting Mendelian genes, so a
    heterozygous CCDC32 loss-of-function finding should NOT be reported as
    disease-causing on constraint grounds. (These are the values returned today;
    the deep-research artifact for this entry quotes pLI 0.19 / LOEUF 0.76 from an
    earlier gnomAD release, and the numbers recorded here are the ones actually
    verified rather than the ones taken from the report.)


    NO CLINGEN VARIANT-LEVEL CURATION EXISTS. `CCDC32[gene]` in the NCBI ClinVar
    esearch endpoint on 2026-08-01 returned 29 variation records, of which five
    are asserted against cardiofacioneurodevelopmental syndrome: four Pathogenic
    (the two frameshift duplications and the two large deletions, all with
    "criteria provided, single submitter" or "no assertion criteria provided"
    review status - none expert-panel reviewed) and one nonsense VUS. No ClinGen
    variant-curation expert-panel assertion and no ClinGen dosage-sensitivity
    curation exists for this gene; see entry note (11).
  inheritance:
  - name: Autosomal recessive
    inheritance_term:
      preferred_term: Autosomal recessive inheritance
      term:
        id: HP:0000007
        label: Autosomal recessive inheritance
    evidence:
    - reference: PMID:41639596
      reference_title: Two siblings with CCDC32-related cardiofacioneurodevelopmental
        syndrome diagnosed by clinical RNA-sequencing and review of literature.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: Cardiofacioneurodevelopmental syndrome (CFNDS, MIM:619123) is a rare
        genetic disorder caused by bi-allelic pathogenic variants in CCDC32.
      explanation: Confirms the biallelic requirement at the gene level.
  evidence:
  - reference: PMID:32307552
    reference_title: Loss of function mutations in CCDC32 cause a congenital syndrome
      characterized by craniofacial, cardiac and neurodevelopmental anomalies.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: Using whole exome sequencing, we identified homozygous frameshift CCDC32
      variants in three affected individuals.
    explanation: The founding gene-disease association.
  - reference: PMID:35451546
    reference_title: "Cardiofacioneurodevelopmental syndrome: Report of a novel patient\
      \ and expansion of the phenotype."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Whole-exome sequencing revealed homozygous loss-of-function variants in\
      \ CCDC32 (alternative name: C15orf57) in both previously described patients."
    explanation: >-
      Independent confirmation of the gene-disease relationship, and the source
      for the alternative gene symbol recorded in the notes.
  - reference: PMID:38818818
    reference_title: "A novel homozygous deletion in CCDC32 gene causing cardiofacioneurodevelopmental\
      \ syndrome: the fourth patient reported."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "A novel homozygous deletion in CCDC32 gene causing cardiofacioneurodevelopmental\
      \ syndrome: the fourth patient reported."
    explanation: >-
      A fourth independent family. This article is indexed in PubMed WITHOUT an
      abstract, so the cached reference body contains only the bibliographic
      header; the quoted text is the article title itself, which is why no
      clinical detail from this report is asserted anywhere in this entry. See
      entry note (5).
  variants:
  - name: CCDC32 c.27dup (p.Thr10fs), family A founding frameshift
    description: >-
      A single-base duplication in the first coding exon of CCDC32, homozygous in
      the 6-year-old girl of the consanguineous Arab Muslim family A reported in
      PMID:32307552 and heterozygous in her unaffected parents and two unaffected
      sibs. It is one of the two alleles that established the gene-disease
      relationship. It is PUBLISHED as NM_001080791.2:c.54dupT p.(Thr19Tyrfs*12)
      and CURATED IN CLINVAR as c.27dup p.Thr10fs on every current transcript
      including the MANE Select NM_001080792.4; the 27-nucleotide (9-codon)
      offset between the two nomenclatures is a transcript-version artefact and
      is explained in the gene-level `notes:` above. Genomic coordinates are
      GRCh38 chr15:40562988-40562989 (GRCh37 chr15:40855187-40855188), matching
      the g.40855188dupA hg19 coordinate cited in the literature. NO ALLELE
      FREQUENCY IS ASSERTED. The ClinVar/OMIM record states the allele "was not
      found in the Greater Middle East Variome, Geno2MP, TOPMed, or gnomAD
      databases", which is an absence rather than a frequency, and the primary
      full text that reports the population screening is not in the reference
      cache (PMID:32307552 is indexed abstract-only; a re-fetch on 2026-08-01
      returned "Content type: abstract_only").
    type: frameshift duplication
    clinical_significance: PATHOGENIC
    sequence_length: 1
    synonyms:
    - NM_001080791.2:c.54dupT
    - p.(Thr19Tyrfs*12)
    - NM_001080792.4:c.27dup
    - p.Thr10fs
    identifiers:
    - ClinVar:VCV000988600
    - OMIM:618941.0001
    - dbSNP:rs1890756020
    - ClinGen:CA1139663846
    gene:
      preferred_term: CCDC32
      term:
        id: hgnc:28295
        label: CCDC32
    external_assertions:
    - name: ClinVar germline classification for CCDC32 c.27dup
      source: ClinVar
      assertion_type: germline_variant_classification
      external_id: VCV000988600
      url: https://www.ncbi.nlm.nih.gov/clinvar/variation/988600/
      description: >-
        Classified Pathogenic for cardiofacioneurodevelopmental syndrome
        (MedGen:C5436852, MONDO:0030873, OMIM:619123), last evaluated 2020-12-09,
        review status "no assertion criteria provided" (one submitter,
        SCV001450459; the OMIM allelic-variant record). Retrieved from the NCBI
        eutils ClinVar esummary and VCV efetch endpoints on 2026-08-01. Recorded
        as a registry identifier rather than as a curated evidence item because
        no `ClinVar:` reference prefix exists in this repository's reference
        cache; see entry note (8).
    functional_effects:
    - description: >-
        Premature termination in the first coding exon. On the isoform numbering
        used by the functional studies this allele is one of the three
        truncations that remove the alpha-helix formed by residues 78 to 98, the
        element required for AP-2 alpha and sigma2 binding.
      type: loss of function
    evidence:
    - reference: PMID:32307552
      reference_title: Loss of function mutations in CCDC32 cause a congenital syndrome
        characterized by craniofacial, cardiac and neurodevelopmental anomalies.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: Using whole exome sequencing, we identified homozygous frameshift CCDC32
        variants in three affected individuals.
      explanation: >-
        The report in which this allele was described. The abstract states the
        allele class and zygosity; the HGVS strings themselves come from the
        ClinVar and OMIM allelic-variant records cited in `identifiers:` and
        `external_assertions:`, because the full text carrying them is not in the
        reference cache.
  - name: CCDC32 c.162_163dup (p.Glu55fs), family B founding frameshift
    description: >-
      A two-base duplication, homozygous in the 3-year-old Iranian boy of
      consanguineous family B reported in PMID:32307552 and heterozygous in his
      unaffected parents. It is the second of the two alleles that established
      the gene-disease relationship, and the allele whose truncated product
      (CCDC32 residues 1 to 54 on the current numbering) was later used as the
      disease-mimic construct in the AP-2 binding experiments. It is PUBLISHED as
      NM_001080791.2:c.189_190dupGG p.(Glu64Glyfs*12) and CURATED IN CLINVAR as
      c.162_163dup p.Glu55fs; the 9-codon offset is the transcript-version
      artefact described in the gene-level `notes:` above. Genomic coordinates
      are GRCh38 chr15:40562852-40562853 (GRCh37 chr15:40855051-40855052),
      matching the g.40855052dupCC coordinate cited in the literature.
    type: frameshift duplication
    clinical_significance: PATHOGENIC
    sequence_length: 2
    synonyms:
    - NM_001080791.2:c.189_190dupGG
    - p.(Glu64Glyfs*12)
    - NM_001080792.4:c.162_163dup
    - p.Glu55fs
    identifiers:
    - ClinVar:VCV000988601
    - OMIM:618941.0002
    - dbSNP:rs1890742129
    - ClinGen:CA1139663845
    gene:
      preferred_term: CCDC32
      term:
        id: hgnc:28295
        label: CCDC32
    external_assertions:
    - name: ClinVar germline classification for CCDC32 c.162_163dup
      source: ClinVar
      assertion_type: germline_variant_classification
      external_id: VCV000988601
      url: https://www.ncbi.nlm.nih.gov/clinvar/variation/988601/
      description: >-
        Classified Pathogenic for cardiofacioneurodevelopmental syndrome
        (MedGen:C5436852, MONDO:0030873, OMIM:619123), last evaluated 2020-12-09,
        review status "no assertion criteria provided" (one submitter,
        SCV001450460; the OMIM allelic-variant record). Retrieved from the NCBI
        eutils ClinVar esummary and VCV efetch endpoints on 2026-08-01.
    functional_effects:
    - description: >-
        Premature termination leaving a product corresponding to the first 54
        residues of CCDC32, which lacks the alpha-helix formed by residues 78 to
        98 and is defective in AP-2 binding.
      type: loss of function
    evidence:
    - reference: PMID:41489497
      reference_title: CCDC32 stabilizes clathrin-coated pits and drives their invagination.
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: "our disease mimic construct CCDC32(1-54) does not contain a 9 aa peptide\
        \ (VRGSCLRFQ) in the N-terminus and an extra 12 aa in the C-terminus when CFNDS\
        \ patient mutation was described (p.(Glu64Glyfs∗12))"
      explanation: >-
        The only place in the reference cache where the published protein-level
        nomenclature for this allele appears, and the direct documentation of the
        9-amino-acid N-terminal offset between the transcript version used by
        PMID:32307552 and the current annotation. This is the primary support for
        the transcript-version hazard recorded in the gene-level `notes:`.
    - reference: PMID:32307552
      reference_title: Loss of function mutations in CCDC32 cause a congenital syndrome
        characterized by craniofacial, cardiac and neurodevelopmental anomalies.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: Using whole exome sequencing, we identified homozygous frameshift CCDC32
        variants in three affected individuals.
      explanation: The report in which this allele was described.
  - name: CCDC32 c.471T>A (p.Tyr157Ter), nonsense variant of uncertain significance
    description: >-
      A nonsense substitution submitted to ClinVar against
      cardiofacioneurodevelopmental syndrome and classified as a variant of
      uncertain significance. It is recorded here because it is the only reported
      CFNDS-associated CCDC32 allele that is NOT pathogenic-classified, and
      because its position matters mechanistically: at codon 157 of a 185-residue
      protein it terminates AFTER the residue 78 to 98 alpha-helix that every
      pathogenic truncation removes, so it is not obviously loss of function by
      the mechanism established for the other alleles. It has no published
      phenotype and no functional characterisation. Do not treat it as a
      confirmed CFNDS allele. No evidence item is attached because there is no
      publication reporting this allele; the only source is the ClinVar
      submission recorded in `external_assertions:` below. This is the one
      variant block in this entry without literature support, and it is flagged
      as such deliberately rather than omitted, because a curator or diagnostic
      laboratory encountering it in ClinVar needs to know that its VUS status has
      not moved.
    type: nonsense
    clinical_significance: UNCERTAIN_SIGNIFICANCE
    sequence_length: 1
    synonyms:
    - NM_001080792.4:c.471T>A
    - p.Tyr157Ter
    identifiers:
    - ClinVar:VCV002580223
    - dbSNP:rs2543087691
    - ClinGen:CA391722033
    gene:
      preferred_term: CCDC32
      term:
        id: hgnc:28295
        label: CCDC32
    external_assertions:
    - name: ClinVar germline classification for CCDC32 c.471T>A
      source: ClinVar
      assertion_type: germline_variant_classification
      external_id: VCV002580223
      url: https://www.ncbi.nlm.nih.gov/clinvar/variation/2580223/
      description: >-
        Classified Uncertain significance for cardiofacioneurodevelopmental
        syndrome (MedGen:C5436852, MONDO:0030873, OMIM:619123), last evaluated
        2023-03-30, review status "criteria provided, single submitter"
        (SCV004035993). GRCh38 chr15:40554058. Retrieved from the NCBI eutils
        ClinVar esummary endpoint on 2026-08-01.
  - name: Truncating variants removing residues 78 to 98
    description: >-
      The three homozygous truncating alleles characterised in the earliest
      reported patients terminate translation such that only the first 9, 54 or
      80 amino acids of the 185-residue protein are produced. All three therefore
      lack the alpha-helix formed by residues 78 to 98, which experimental
      deletion shows is required for binding the AP-2 alpha subunit. This is the
      structural basis of the loss of function. This block is the CLASS-level
      statement of that shared structural consequence. The individual alleles it
      covers are curated separately above (`CCDC32 c.27dup` and `CCDC32
      c.162_163dup`) with their HGVS, ClinVar, OMIM, dbSNP and ClinGen
      identifiers; the third truncation, the one expressing the first 80
      residues, is described only by its truncation position in PMID:41489497 and
      has no matching ClinVar record identifiable by a `CCDC32[gene]` ClinVar
      esearch on 2026-08-01, so it is not broken out as its own allele block.
    type: nonsense and frameshift
    clinical_significance: PATHOGENIC
    gene:
      preferred_term: CCDC32
      term:
        id: hgnc:28295
        label: CCDC32
    functional_effects:
    - description: >-
        Abolishes the interaction between CCDC32 and AP2 and inhibits
        clathrin-mediated endocytosis. A patient-derived construct expressing
        only the first 54 residues failed to co-immunoprecipitate AP2, was not
        recruited to clathrin-coated pits, and did not rescue transferrin uptake.
      type: loss of function
    evidence:
    - reference: PMID:41489497
      reference_title: CCDC32 stabilizes clathrin-coated pits and drives their invagination.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: Clinical genome sequencing of three patients with cardio-facio-neuro-developmental
        syndrome (CFNDS) revealed three homozygous nonsense mutations that only express
        the first 9, 54, and 80 aa of CCDC32, respectively
      explanation: Specifies the three truncation positions in the reported patients.
    - reference: PMID:41489497
      reference_title: CCDC32 stabilizes clathrin-coated pits and drives their invagination.
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: These findings show that this loss-of-function nonsense mutation in CCDC32
        abolishes its interactions with AP2 and inhibits CME, likely contributing to
        the development of CFNDS.
      explanation: >-
        Functional characterisation of a patient-derived truncation in a human
        cell line.
    - reference: PMID:41489497
      reference_title: CCDC32 stabilizes clathrin-coated pits and drives their invagination.
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: Deletion of aa78-98 in CCDC32, corresponding to a predicted alpha-helix,
        abrogates AP2 binding
      explanation: >-
        Identifies the functional element that all three truncations remove.
  - name: Multi-exon and whole-gene CCDC32 deletions
    description: >-
      Structural deletions are a recurrent class of CFNDS allele. Reported
      examples are a homozygous 32,583 bp deletion affecting CCDC32, a further
      novel homozygous deletion in an unrelated fourth patient, and a biallelic
      deletion of exons 3 and 4 detected only through RNA sequencing. These
      alleles are important diagnostically because they can be missed by SNP
      array and by exome sequencing. The two whole-gene deletions carry ClinVar
      coordinates NC_000015.10:g.40529942_40562524del (the Abdalla patient) and
      NC_000015.10:g.(40529939_40562522)del (the Fernandes da Rocha patient),
      which differ by only 2 to 3 base pairs at each breakpoint despite coming
      from unrelated patients ascertained at different centres; see the
      `ccdc32_recurrent_15q15_deletion` discussion for what that may and may not
      mean.
    type: deletion
    clinical_significance: PATHOGENIC
    identifiers:
    - ClinVar:VCV001690313
    - ClinVar:VCV002431643
    - OMIM:618941.0003
    gene:
      preferred_term: CCDC32
      term:
        id: hgnc:28295
        label: CCDC32
    external_assertions:
    - name: ClinVar germline classification for the CCDC32 32.6-kb deletion (Abdalla
        patient)
      source: ClinVar
      assertion_type: germline_variant_classification
      external_id: VCV001690313
      url: https://www.ncbi.nlm.nih.gov/clinvar/variation/1690313/
      description: >-
        NC_000015.10:g.40529942_40562524del, alias "32.6-KB DEL", classified
        Pathogenic for cardiofacioneurodevelopmental syndrome, last evaluated
        2022-11-29, review status "criteria provided, single submitter"; also
        carried as OMIM allelic variant 618941.0003. GRCh37 coordinates
        chr15:40822141-40854723. Retrieved from the NCBI eutils ClinVar esummary
        endpoint on 2026-08-01.
    - name: ClinVar germline classification for the CCDC32 whole-gene deletion (Fernandes
        da Rocha patient)
      source: ClinVar
      assertion_type: germline_variant_classification
      external_id: VCV002431643
      url: https://www.ncbi.nlm.nih.gov/clinvar/variation/2431643/
      description: >-
        NC_000015.10:g.(40529939_40562522)del, classified Pathogenic for
        cardiofacioneurodevelopmental syndrome, last evaluated 2022-06-03, review
        status "criteria provided, single submitter" (SCV003807749). The
        parenthesised coordinates denote uncertain breakpoints. Retrieved from
        the NCBI eutils ClinVar esummary endpoint on 2026-08-01.
    evidence:
    - reference: PMID:35451546
      reference_title: "Cardiofacioneurodevelopmental syndrome: Report of a novel patient\
        \ and expansion of the phenotype."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: We report a 9-year-old female patient with CFNDS caused by a homozygous
        32,583-bp deletion affecting CCDC32.
      explanation: The first reported structural deletion allele.
    - reference: PMID:35451546
      reference_title: "Cardiofacioneurodevelopmental syndrome: Report of a novel patient\
        \ and expansion of the phenotype."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: Independent of the affected CCDC32 transcript variant this deletion likely
        leads to loss of the encoded protein.
      explanation: >-
        Explains why the deletion is interpreted as loss of function regardless
        of which transcript is considered.
    - reference: PMID:41639596
      reference_title: Two siblings with CCDC32-related cardiofacioneurodevelopmental
        syndrome diagnosed by clinical RNA-sequencing and review of literature.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: Skipping of two exons in CCDC32 transcript was identified, consistent
        with a bi-allelic deletion including exons 3 and 4 of CCDC32.
      explanation: An intragenic multi-exon deletion detected through its transcript consequence.
diagnosis:
- name: Exome or genome sequencing
  description: >-
    The diagnosis is molecular. Every reported family was solved by sequencing,
    and in the consanguineous families homozygosity for a truncating CCDC32
    allele was the finding. A child with bilateral cleft lip and palate together
    with developmental delay, and particularly one with additional cardiac,
    laterality or posterior-fossa findings, is the phenotype in which CCDC32
    should be considered.
  evidence:
  - reference: PMID:32307552
    reference_title: Loss of function mutations in CCDC32 cause a congenital syndrome
      characterized by craniofacial, cardiac and neurodevelopmental anomalies.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: Using whole exome sequencing, we identified homozygous frameshift CCDC32
      variants in three affected individuals.
    explanation: >-
      Exome sequencing was the method that established the diagnosis in the
      founding families.
- name: RNA sequencing when DNA-based testing is uninformative
  description: >-
    Because a substantial share of CFNDS alleles are structural deletions, DNA
    based first-line testing can miss the diagnosis. In one family a biallelic
    deletion of exons 3 and 4 was invisible to both SNP array and trio exome
    sequencing and was found only because clinical RNA sequencing detected
    skipping of the two exons in the CCDC32 transcript. RNA sequencing should
    therefore be considered in a phenotypically compatible child whose DNA-based
    work-up is negative.
  evidence:
  - reference: PMID:41639596
    reference_title: Two siblings with CCDC32-related cardiofacioneurodevelopmental
      syndrome diagnosed by clinical RNA-sequencing and review of literature.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: We present a family with two affected individuals who were diagnosed through
      clinical RNA sequencing (RNA-seq) after conventional DNA diagnostics did not yield
      a molecular cause.
    explanation: >-
      States precisely the diagnostic claim made here: RNA sequencing made the
      diagnosis after DNA-based testing had failed.
  - reference: PMID:41639596
    reference_title: Two siblings with CCDC32-related cardiofacioneurodevelopmental
      syndrome diagnosed by clinical RNA-sequencing and review of literature.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: This deletion was not detected in previous SNP array analyses and trio
      exome sequencing focusing on genes related to intellectual disability and congenital
      malformations, highlighting the complementary value of RNA-seq.
    explanation: >-
      Documents that both SNP array and trio exome sequencing missed the causal
      allele, which is the reason RNA sequencing is recommended here.
- name: Brain magnetic resonance imaging
  description: >-
    Brain imaging is indicated because midline and posterior-fossa anomalies are
    part of the phenotype and are not detectable clinically. Hypoplasia of the
    corpus callosum and cerebellar hypoplasia have both been reported.
  evidence:
  - reference: PMID:35451546
    reference_title: "Cardiofacioneurodevelopmental syndrome: Report of a novel patient\
      \ and expansion of the phenotype."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: Brain imaging disclosed hypoplastic corpus callosum.
    explanation: >-
      Brain imaging revealed a structural anomaly that would otherwise have been
      missed.
treatments:
- name: Antimicrobial prophylaxis and immunisation for asplenia
  description: >-
    In the subset of individuals with asplenia, lifelong antibiotic prophylaxis
    (conventionally penicillin), an asplenia immunisation schedule against
    encapsulated organisms, and a low threshold for empiric treatment of febrile
    illness are indicated. This is the only pharmacological intervention in the
    syndrome with a specific indication rather than a purely symptomatic one, and
    it is the reason abdominal imaging for spleen and situs belongs in the
    baseline evaluation. It follows generic asplenia protocols; no CFNDS-specific
    protocol exists.
  therapeutic_modality: SMALL_MOLECULE
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
  target_phenotypes:
  - preferred_term: Asplenia
    term:
      id: HP:0001746
      label: Asplenia
- name: Cleft palate repair
  description: >-
    Surgical closure of the palatal cleft (palatoplasty/palatorrhaphy), typically
    at around 9 to 18 months and timed to speech development, within a
    multidisciplinary cleft team that also manages feeding, hearing and
    dentition. This is standard cleft care and is not specific to CFNDS; no
    CFNDS-specific surgical outcome data exist. The timing relative to speech
    acquisition is why this treatment is coordinated with the speech and language
    therapy entry below.
  therapeutic_modality: SURGERY
  treatment_term:
    preferred_term: palatorrhaphy
    term:
      id: NCIT:C168380
      label: Palatorrhaphy
  target_phenotypes:
  - preferred_term: Cleft palate
    term:
      id: HP:0000175
      label: Cleft palate
- name: Cleft lip repair
  description: >-
    Surgical closure of the cleft lip (cheiloplasty), conventionally in the first
    months of life, addressing lip competence, feeding and facial appearance.
    Split from palatal repair because the two procedures have different timing,
    different functional targets and different NCIT identities; NCIT has no
    cheiloplasty-specific clinical-action term reachable from NCIT:C25218 that
    `just validate-terms` accepts, so the generic surgical-procedure term is
    retained here while the palatal arm uses the specific term. Standard cleft
    care, not CFNDS-specific.
  therapeutic_modality: SURGERY
  treatment_term:
    preferred_term: cleft lip repair (cheiloplasty)
    term:
      id: NCIT:C15329
      label: Surgical Procedure
  target_phenotypes:
  - preferred_term: Cleft lip
    term:
      id: HP:0410030
      label: Cleft lip
- name: Nutritional and feeding support in infancy
  description: >-
    Feeding difficulties in infancy are reported in every fully described CFNDS
    infant and have two convergent causes here: the orofacial cleft itself, which
    prevents an effective seal, and the neurodevelopmental component. Management
    is cleft-specific feeding equipment and positioning, calorie supplementation
    and growth monitoring, escalating to gastrostomy if feeding failure is
    severe. This closes the loop on the promoted Feeding difficulties in infancy
    phenotype: it was promoted from the HPO annotation set under the
    "changes management" rule in entry note (10), and this is the management it
    changes. Generic supportive care, not CFNDS-specific.
  therapeutic_modality: OTHER
  treatment_term:
    preferred_term: nutritional support
    term:
      id: NCIT:C15433
      label: Nutritional Support
  target_phenotypes:
  - preferred_term: Feeding difficulties in infancy
    term:
      id: HP:0008872
      label: Feeding difficulties in infancy
- name: Orchidopexy for cryptorchidism
  description: >-
    Surgical orchidopexy for undescended testis, conventionally between 6 and 18
    months of age, following general paediatric urology practice rather than any
    CFNDS-specific protocol. Included because cryptorchidism was promoted into
    the `phenotypes:` list under the "changes management" rule in entry note
    (10), and this is the management it changes: the phenotype is only worth
    recording if it triggers examination and referral within the window in which
    orchidopexy protects fertility and reduces malignancy risk. Reported in one
    of the two index individuals (HPO annotation 1/1); no CFNDS-specific
    urological outcome data exist.
  therapeutic_modality: SURGERY
  treatment_term:
    preferred_term: orchiopexy
    term:
      id: NCIT:C111066
      label: Orchiopexy
  target_phenotypes:
  - preferred_term: Cryptorchidism
    term:
      id: HP:0000028
      label: Cryptorchidism
- name: Audiological surveillance and hearing support
  description: >-
    Bilateral conductive hearing loss has been reported and is expected in a
    child with cleft palate. Regular audiometry, treatment of middle-ear effusion
    and amplification where indicated protect the speech and language development
    that is already at risk from the neurodevelopmental component.
  therapeutic_modality: OTHER
  treatment_term:
    preferred_term: supportive care
    term:
      id: NCIT:C15747
      label: Supportive Care
- name: Speech and language therapy
  description: >-
    A high priority in this syndrome specifically, because three separate
    contributors converge on speech: the palatal cleft itself, the conductive
    hearing loss that accompanies it, and the global developmental delay. Therapy
    should be coordinated with the timing of palatoplasty and with audiological
    management.
  therapeutic_modality: BEHAVIORAL
  treatment_term:
    preferred_term: speech therapy
    term:
      id: NCIT:C159273
      label: Speech Language Therapy
- name: Developmental and educational therapy
  description: >-
    Early intervention, physical and occupational therapy, and an individualised
    educational programme, directed at the developmental delay and intellectual
    disability. Symptomatic and supportive only.
  therapeutic_modality: BEHAVIORAL
  treatment_term:
    preferred_term: rehabilitation
    term:
      id: NCIT:C15315
      label: Rehabilitation
- name: Cardiac evaluation and management
  description: >-
    Echocardiography at diagnosis, with cardiology follow-up and surgical repair
    of any structural lesion according to standard congenital heart disease
    practice. No lesion pattern specific to CFNDS has been defined.
  therapeutic_modality: OTHER
  treatment_term:
    preferred_term: supportive care
    term:
      id: NCIT:C15747
      label: Supportive Care
- name: Genetic counselling
  description: >-
    CFNDS is autosomal recessive, so unaffected carrier parents have a 25%
    recurrence risk in each pregnancy. Several reported families were
    consanguineous. Once the familial alleles are known, carrier testing and
    prenatal or preimplantation testing become available. Counselling should note
    that structural deletions are a common allele class and that a targeted
    deletion assay, rather than sequencing alone, may be needed for accurate
    carrier testing.
  therapeutic_modality: OTHER
  treatment_term:
    preferred_term: genetic counseling
    term:
      id: NCIT:C15240
      label: Genetic Counseling
differential_diagnoses:
- name: Cardiofaciocutaneous syndrome
  description: >-
    A RASopathy caused by heterozygous gain-of-function variants in BRAF,
    MAP2K1, MAP2K2 or KRAS. It is included here primarily as a NAMING hazard
    rather than a close clinical mimic: "cardiofaciocutaneous" and
    "cardiofacioneurodevelopmental" differ by one word element, both abbreviate
    to a CF acronym, and a literature search or an automated entity resolver can
    silently substitute one for the other. Clinically the two do share
    craniofacial dysmorphism, congenital heart disease, growth retardation and
    intellectual disability, so the distinction also matters at the bedside. The
    discriminators are the ectodermal features and the inheritance pattern.
  distinguishing_features:
  - Autosomal dominant, usually de novo, versus autosomal recessive for CFNDS
  - Caused by RAS-MAPK pathway genes (BRAF, MAP2K1, MAP2K2, KRAS), not CCDC32
  - Hyperkeratotic skin and sparse curly hair are cardinal, and have not been reported
    in CFNDS
  - Bilateral cleft lip and palate is the core craniofacial feature of CFNDS but is
    not characteristic of cardiofaciocutaneous syndrome
  - Pulmonic stenosis and hypertrophic cardiomyopathy are the characteristic RASopathy
    cardiac lesions
  disease_term:
    preferred_term: cardiofaciocutaneous syndrome
    term:
      id: MONDO:0015280
      label: cardiofaciocutaneous syndrome
  notes: >-
    Verified not to be an ancestor of MONDO:0030873. `runoak -i sqlite:obo:mondo
    ancestors MONDO:0030873` returns only MONDO:0003847 (hereditary disease),
    MONDO:7770008, MONDO:7770009, MONDO:0000001 and MONDO:0700096 above this
    entry, none of which is MONDO:0015280.
  evidence:
  - reference: PMID:20301365
    reference_title: Cardiofaciocutaneous Syndrome.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "CLINICAL CHARACTERISTICS: Cardiofaciocutaneous (CFC) syndrome is characterized\
      \ by cardiac abnormalities (pulmonic stenosis and other valve dysplasias, septal\
      \ defects, hypertrophic cardiomyopathy, rhythm disturbances), distinctive craniofacial\
      \ appearance, and cutaneous abnormalities"
    explanation: >-
      The GeneReviews definition of the differential, showing that the cutaneous
      component is cardinal to it and absent from CFNDS.
  - reference: PMID:20301365
    reference_title: Cardiofaciocutaneous Syndrome.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: The diagnosis of CFC syndrome is established in a proband with suggestive
      clinical findings by the identification of a heterozygous pathogenic variant in
      BRAF, MAP2K1, MAP2K2, or KRAS by molecular genetic testing.
    explanation: >-
      Establishes the genetic discriminator: heterozygous RAS-MAPK pathway
      variants rather than biallelic CCDC32 variants.
  - reference: PMID:20301365
    reference_title: Cardiofaciocutaneous Syndrome.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: CFC syndrome is inherited in an autosomal dominant manner.
    explanation: Establishes the inheritance discriminator.
- name: AP2M1-related intellectual developmental disorder with seizures
  description: >-
    Caused by heterozygous de novo variants in AP2M1, which encodes the mu2
    subunit of the same AP-2 complex that CCDC32 assembles. This is the
    mechanistically closest human disorder: it disrupts the same endpoint from
    inside the complex rather than from the chaperone that builds it. The
    phenotypes diverge, which is itself informative, since AP2M1 disease is a
    dominant epileptic-encephalopathy-like neurodevelopmental phenotype without
    the orofacial clefting and laterality anomalies that define CFNDS.
  distinguishing_features:
  - Autosomal dominant de novo, versus autosomal recessive for CFNDS
  - Caused by AP2M1 (HGNC:564), an AP-2 subunit, rather than CCDC32, the AP-2 assembly
    chaperone
  - Seizures are a defining feature, and have not been reported in CFNDS
  - Orofacial clefting, laterality anomalies and congenital cardiac malformation are
    not features
  disease_term:
    preferred_term: AP2M1-related intellectual developmental disorder with seizures
    term:
      id: MONDO:0032823
      label: intellectual developmental disorder 60 with seizures
  notes: >-
    The MONDO binding was verified by `runoak -i sqlite:obo:mondo relationships
    --direction both HGNC:564`, which returns MONDO:0032823 with predicate
    RO:0004003 for AP2M1. The evidence items below characterise the DIFFERENTIAL
    entity, not CFNDS; no claim about CFNDS is sourced from them.
  evidence:
  - reference: PMID:31104773
    reference_title: A Recurrent Missense Variant in AP2M1 Impairs Clathrin-Mediated
      Endocytosis and Causes Developmental and Epileptic Encephalopathy.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: We subsequently found the same de novo variant in two individuals with
      neurodevelopmental disorders and generalized epilepsy in a cohort of 2,310 individuals
      who underwent diagnostic whole-exome sequencing.
    explanation: >-
      Establishes the de novo dominant inheritance and the epilepsy-dominated
      phenotype that discriminate this disorder from CFNDS.
  - reference: PMID:31104773
    reference_title: A Recurrent Missense Variant in AP2M1 Impairs Clathrin-Mediated
      Endocytosis and Causes Developmental and Epileptic Encephalopathy.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: We identified a de novo c.508C>T (p.Arg170Trp) variant in AP2M1 in two
      individuals with a phenotypic similarity that was higher than expected by chance
      (p = 0.003) and a phenotype related to epilepsy with myoclonic-atonic seizures.
    explanation: >-
      Names the recurrent allele and the seizure phenotype, neither of which has
      a counterpart in CFNDS.
- name: Ciliopathy with craniofacial, cardiac and laterality involvement
  description: >-
    The founding report explicitly framed CFNDS as overlapping the ciliopathies,
    on the basis of the laterality anomalies and the craniofacial and brain
    findings. In practice a child with orofacial clefting, a congenital cardiac
    lesion, situs abnormality and posterior-fossa anomaly will be worked up for
    the ciliopathy spectrum, and CCDC32 should be in that differential rather
    than outside it. No single MONDO grouping term is bound here because the
    candidate entities span several distinct disorders rather than one, and
    picking any one of them would assert a specific alternative diagnosis that
    the source does not support.
  distinguishing_features:
  - Retinal degeneration, cystic kidney disease and postaxial polydactyly are cardinal
    in the classic ciliopathies and have not been reported in CFNDS
  - Bilateral cleft lip and palate is the core CFNDS feature and is not typical of
    the classic ciliopathies
  - CFNDS is caused by CCDC32, which is an AP-2 assembly chaperone rather than a
    structural or transport component of the cilium
  evidence:
  - reference: PMID:32307552
    reference_title: Loss of function mutations in CCDC32 cause a congenital syndrome
      characterized by craniofacial, cardiac and neurodevelopmental anomalies.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: Because some of the patient phenotypes overlap defects common to ciliopathies,
      we asked if loss of CCDC32 might contribute to the dysfunction of this organelle.
    explanation: >-
      The authors themselves note the phenotypic overlap with ciliopathies, which
      is the reason this differential is listed.
animal_models:
- species: Danio rerio
  genotype: Morpholino and deletion depletion of ccdc32 in zebrafish embryos
  description: >-
    Depletion of the zebrafish orthologue of CCDC32 reproduces the human
    malformation pattern and impairs cilium formation. This is the only in vivo
    model of the disorder that has been published, and it is the sole source of
    the ciliary arm of the proposed pathomechanism. A second, independent
    zebrafish deletion experiment was reported in PMID:35451546. No mouse model
    of Ccdc32 deficiency was located during curation.
  genes:
  - preferred_term: ccdc32
    term:
      id: hgnc:28295
      label: CCDC32
  associated_phenotypes:
  - Craniofacial anomaly
  - Cardiac anomaly
  - Impaired ciliogenesis
  evidence:
  - reference: PMID:32307552
    reference_title: Loss of function mutations in CCDC32 cause a congenital syndrome
      characterized by craniofacial, cardiac and neurodevelopmental anomalies.
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: Functional analysis in a zebrafish model revealed that ccdc32 depletion
      recapitulates the human phenotypes.
    explanation: >-
      Establishes face validity of the model for the human malformation
      phenotype.
  - reference: PMID:35451546
    reference_title: "Cardiofacioneurodevelopmental syndrome: Report of a novel patient\
      \ and expansion of the phenotype."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: ccdc32 deletion in zebrafish suggests a ciliary contribution to the pathomechanism.
    explanation: >-
      A second report of the zebrafish result, restating the ciliary
      interpretation.
discussions:
- discussion_id: ccdc32_ap2_versus_cilia
  kind: OPEN_QUESTION
  status: OPEN
  prompt: >-
    Do the craniofacial, cardiac and brain malformations of CFNDS arise from the
    endocytic consequences of failed AP-2 assembly, from a ciliary defect, or
    from both?
  attaches_to:
  - pathophysiology#Defective Ciliogenesis
  - pathophysiology#Deficient Clathrin-Mediated Endocytosis
  rationale: >-
    The endocytic arm has by far the stronger molecular evidence: three
    independent structural and cell-biological studies published between 2024 and
    2026 converge on CCDC32 being the assembly chaperone of AP-2, and a
    patient-derived truncation has been shown directly to abolish AP2 binding and
    inhibit endocytosis. The ciliary arm rests on one 2020 paper, has not been
    replicated, and was hedged by its own authors as being "at least partially"
    involved. But the endocytic arm has never been connected to a human
    malformation: its supporting argument for the developmental phenotype is the
    resemblance between CFNDS and mouse AP2-subunit knockouts, which is an
    analogy rather than a demonstration. Meanwhile the laterality anomalies in the
    founding families are hard to explain from endocytosis alone and are the
    canonical readout of motile-cilium dysfunction. The two models are not
    mutually exclusive, because clathrin-mediated endocytosis participates in
    ciliary membrane trafficking, so an endocytic primary defect could produce a
    secondary ciliary phenotype. Resolving this would require examining cilia in
    cells carrying a patient CCDC32 genotype, which no published study has done.
  notes: >-
    Both edges into the morphogenesis node are curated as
    INDIRECT_UNKNOWN_INTERMEDIATES precisely because of this gap.
  evidence:
  - reference: PMID:32307552
    reference_title: Loss of function mutations in CCDC32 cause a congenital syndrome
      characterized by craniofacial, cardiac and neurodevelopmental anomalies.
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: arguing that ciliary defects are at least partially involved in the pathomechanism
      of this disorder
    explanation: >-
      The ciliary side of the question, stated by its own authors as a partial
      explanation, which is the hedge that keeps the question open.
  - reference: PMID:41489497
    reference_title: CCDC32 stabilizes clathrin-coated pits and drives their invagination.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: Our results suggest that the inability to bind mature AP2 and hence to
      be recruited to nascent CCSs inhibits critical early stages of CME and contributes
      to the development of CFNDS.
    explanation: >-
      The endocytic side of the question, also phrased as a suggestion and a
      contribution rather than as a demonstrated cause.
- discussion_id: ccdc32_ap2_chaperone_mechanism
  kind: CONTROVERSY
  status: OPEN
  prompt: >-
    Is CCDC32 a transient assembly chaperone that is released before AP-2
    matures, or does it also bind the mature complex and act at clathrin-coated
    pits?
  attaches_to:
  - pathophysiology#Failure of AP-2 Adaptor Complex Assembly
  - pathophysiology#Clathrin-Coated Pit Destabilization
  rationale: >-
    PMID:39145939 reconstituted an ordered handover in which AAGAB initiates
    assembly, CCDC32 forms a ternary template that recruits the remaining
    subunits, and CCDC32 is then released; those authors could not detect
    interaction between a C-terminally tagged CCDC32 and the mature AP2 complex.
    PMID:41489497 reports the opposite on that point, finding that CCDC32 binds
    full-length AP2 complexes in cells, is recruited to clathrin-coated pits, and
    is required for their stabilisation and invagination, and it notes the
    discrepancy explicitly. PMID:42234739 adds a third layer: in solution CCDC32
    prevents assembly and actively disassembles AP-2 tetramers, and it is the
    presence of PIP2-containing membrane that permits assembly to complete, so
    the protein is proposed to be an inhibitor released by a membrane switch. The
    disagreement may be partly technical, since the tagging strategy differs
    between studies, but it is unresolved. For CFNDS the practical consequence is
    limited: on all three models, a truncation that removes the AP-2-binding
    helix is loss of function.
  evidence:
  - reference: PMID:42234739
    reference_title: CCDC32 collaborates with the membrane to assemble the AP-2 clathrin
      adaptor complex.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: Unexpectedly, in solution, CCDC32 prevents complex assembly and actively
      disassembles AP-2 tetramers.
    explanation: >-
      The third and most recent model, in which CCDC32 is inhibitory until
      membrane relieves the inhibition.
  - reference: PMID:42234739
    reference_title: CCDC32 collaborates with the membrane to assemble the AP-2 clathrin
      adaptor complex.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: We propose that the membrane acts as a molecular switch to release inhibitory
      interactions, allowing for full complex assembly to proceed.
    explanation: The proposed reconciliation, which is itself a hypothesis.
- discussion_id: ccdc32_hypomorph_versus_null
  kind: OPEN_QUESTION
  status: OPEN
  prompt: >-
    Are the reported CFNDS alleles true nulls, or must they retain residual
    function for the pregnancy to be viable?
  attaches_to:
  - pathophysiology#Biallelic CCDC32 Loss of Function
  rationale: >-
    Complete loss of CCDC32 abolishes AP-2 complexes, and complete loss of AP2
    has been reported to be embryonic lethal in Drosophila and zebrafish. The
    authors of PMID:41489497 therefore argue that the human CFNDS alleles must be
    hypomorphic rather than null, while acknowledging that nonsense-mediated
    decay could instead mean the truncated proteins are simply not expressed. One
    of the reported CFNDS conceptions was a terminated fetus, which is at least
    consistent with severe alleles being poorly tolerated. Distinguishing these
    possibilities requires measuring CCDC32 transcript and protein in patient
    cells, which has not been reported.
  notes: >-
    This question bears directly on whether a constitutive knockout would be a
    valid model of the human disease. No such model has been published, so the
    issue is recorded rather than resolved.
  evidence:
  - reference: PMID:41489497
    reference_title: CCDC32 stabilizes clathrin-coated pits and drives their invagination.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: we suggest that the disease-associated CFNDS mutants are hypomorphic
    explanation: The hypomorph side of the question, phrased by its authors as a suggestion.
  - reference: PMID:41489497
    reference_title: CCDC32 stabilizes clathrin-coated pits and drives their invagination.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: While we cannot rule out nonsense-mediated decay and resulting loss of
      expression of the truncated human mutations
    explanation: >-
      The competing possibility, that the alleles are effectively null because
      the transcripts are degraded, acknowledged by the same authors.
- discussion_id: ccdc32_recurrent_15q15_deletion
  kind: KNOWLEDGE_GAP
  status: OPEN
  prompt: >-
    Are the two large CCDC32 deletions a single recurrent allele generated by
    non-allelic homologous recombination at 15q15.1, or a founder allele, or
    coincidentally similar independent events?
  attaches_to:
  - pathophysiology#Biallelic CCDC32 Loss of Function
  rationale: >-
    Three of the five reported CFNDS families carry a structural deletion rather
    than a point mutation, which is an unusually high proportion for a gene this
    small, and two of those deletions have near-identical breakpoints. ClinVar
    records the Abdalla allele as NC_000015.10:g.40529942_40562524del
    (VCV001690313) and the Fernandes da Rocha allele as
    NC_000015.10:g.(40529939_40562522)del (VCV002431643) - a difference of 3 bp at
    the proximal breakpoint and 2 bp at the distal one, between patients
    ascertained independently in Egypt/Hamburg and in Porto. Two mechanisms would
    explain that: a repeat-mediated recurrent rearrangement, in which flanking
    low-copy repeats at 15q15.1 make the same deletion arise repeatedly by
    non-allelic homologous recombination, or a shared founder haplotype. The two
    have opposite consequences for practice. A recurrent NAHR allele would mean
    the deletion arises de novo at appreciable frequency in any population, that
    a targeted breakpoint assay would be a worthwhile first-line test worldwide,
    and that carrier screening cannot be restricted by ancestry. A founder allele
    would confine that reasoning to one population. Nothing published
    distinguishes them: no segmental-duplication analysis of the interval has
    been reported, neither paper reports a breakpoint junction sequence, no
    haplotype has been typed across the two families, and the difference of a few
    base pairs may be nothing more than differing CNV-calling resolution between
    two laboratories rather than a real difference in the alleles. Resolving this
    needs breakpoint-junction sequencing in both families plus a repeat-content
    analysis of 15q15.1; both are straightforward and neither has been done.
  notes: >-
    THIS IS A HYPOTHESIS, NOT A FINDING, AND IS CURATED AS A KNOWLEDGE GAP FOR
    THAT REASON. The breakpoint coordinates quoted in the rationale are ClinVar
    record fields retrieved from the NCBI eutils ClinVar esummary endpoint on
    2026-08-01, not statements made by either publication; the Fernandes da Rocha
    report (PMID:38818818) is indexed in PubMed without an abstract and its full
    text is not in the reference cache, so no evidence item can quote its
    breakpoints and the inference is explicitly not attributed to its authors.
    The ClinVar coordinates for that allele are additionally parenthesised, which
    in HGVS notation means the breakpoints are uncertain - so the apparent
    2-to-3-bp difference may not be a real difference at all. The lead was raised
    in section 4.2 of the deep-research artifact for this entry and is recorded
    here rather than dropped, with its provenance and its unresolved status
    stated, because it is testable and consequential.
  evidence:
  - reference: PMID:35451546
    reference_title: "Cardiofacioneurodevelopmental syndrome: Report of a novel patient\
      \ and expansion of the phenotype."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: We report a 9-year-old female patient with CFNDS caused by a homozygous
      32,583-bp deletion affecting CCDC32.
    explanation: >-
      The first of the two deletion alleles whose breakpoints are being compared,
      and the only one whose size is stated in a quotable published text.
  - reference: PMID:38818818
    reference_title: "A novel homozygous deletion in CCDC32 gene causing cardiofacioneurodevelopmental\
      \ syndrome: the fourth patient reported."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "A novel homozygous deletion in CCDC32 gene causing cardiofacioneurodevelopmental\
      \ syndrome: the fourth patient reported."
    explanation: >-
      Establishes that a second, independently ascertained homozygous CCDC32
      deletion exists. The quoted text is the article title, because this report
      is indexed without an abstract; see entry note (5). Note that the authors
      call their allele "novel", which is a claim of independence rather than of
      recurrence, and that they had no way to compare breakpoints with the
      earlier report.
- discussion_id: ccdc32_expressivity_with_loss_of_function_alleles
  kind: OPEN_QUESTION
  status: OPEN
  prompt: >-
    Why is expressivity so variable between individuals when every reported
    allele is a complete loss of function?
  attaches_to:
  - pathophysiology#Biallelic CCDC32 Loss of Function
  - phenotypes#Hypertelorism
  rationale: >-
    Every CFNDS allele reported to date is a truncation or a deletion, so there
    is no obvious allelic-series explanation for phenotypic differences. Yet the
    two index individuals differed in opposite directions on the same midline
    measurement, one being hypoteloric and the other hyperteloric, and the
    cardiac phenotype ranged from an atrioventricular canal defect with asplenia
    and abdominal situs inversus in one to an isolated ventricular septal defect
    with pulmonic stenosis in the other. Candidate explanations are unmapped
    modifier loci, differences in residual transcript escaping nonsense-mediated
    decay, and stochastic variation in a threshold-sensitive developmental
    process. None has been tested. The practical consequence is that no
    genotype-based prognostic counselling is possible.
  notes: >-
    The hypertelorism/hypotelorism discordance is taken from the HPO annotation
    for OMIM:619123 (both at 1/2, source PMID:32307552) and from the separately
    evidenced hypertelorism in PMID:35451546; it is recorded in the `notes:` of
    the two corresponding phenotypes rather than as an evidence item, because the
    underlying counts come from a full text that is not in the reference cache.
- discussion_id: ccdc32_phenotype_denominator_gap
  kind: KNOWLEDGE_GAP
  status: OPEN
  prompt: >-
    What is the true frequency of each CFNDS feature, and what is the natural
    history beyond childhood?
  rationale: >-
    Fewer than ten affected individuals have been reported, in four separate
    papers, with non-uniform investigation: not every patient is documented as
    having had brain imaging, echocardiography or audiometry, so an apparent
    absence of a feature may be an absence of testing. No prospective natural
    history study, no survival data, no adult outcome and no population
    prevalence or carrier frequency exists. This entry therefore asserts no
    frequency band on any phenotype and no prevalence rate. The gap will close
    only through a multicentre case collection, which the diagnostic difficulty
    documented in PMID:41639596 suggests is likely to keep growing as RNA
    sequencing enters routine practice.
  evidence:
  - reference: PMID:41639596
    reference_title: Two siblings with CCDC32-related cardiofacioneurodevelopmental
      syndrome diagnosed by clinical RNA-sequencing and review of literature.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: So far, CFNDS has only been described in four living individuals and one
      terminated fetus from four families
    explanation: >-
      Quantifies the denominator problem: no frequency or natural-history claim
      can be made from a cohort of this size.
references:
- reference: PMID:32307552
  title: Loss of function mutations in CCDC32 cause a congenital syndrome characterized
    by craniofacial, cardiac and neurodevelopmental anomalies.
- reference: PMID:35451546
  title: "Cardiofacioneurodevelopmental syndrome: Report of a novel patient and expansion\
    \ of the phenotype."
- reference: PMID:38818818
  title: "A novel homozygous deletion in CCDC32 gene causing cardiofacioneurodevelopmental\
    \ syndrome: the fourth patient reported."
- reference: PMID:41639596
  title: Two siblings with CCDC32-related cardiofacioneurodevelopmental syndrome diagnosed
    by clinical RNA-sequencing and review of literature.
- reference: PMID:33859415
  title: A genome-wide atlas of co-essential modules assigns function to uncharacterized
    genes.
- reference: PMID:39145939
  title: An AAGAB-to-CCDC32 handover mechanism controls the assembly of the AP2 adaptor
    complex.
- reference: PMID:41489497
  title: CCDC32 stabilizes clathrin-coated pits and drives their invagination.
- reference: PMID:42234739
  title: CCDC32 collaborates with the membrane to assemble the AP-2 clathrin adaptor
    complex.
- reference: PMID:31104773
  title: A Recurrent Missense Variant in AP2M1 Impairs Clathrin-Mediated Endocytosis
    and Causes Developmental and Epileptic Encephalopathy.
- reference: PMID:20301365
  title: Cardiofaciocutaneous Syndrome.
  tags:
  - GeneReviews

📚

References & Deep Research

References

10

PMID:32307552

Loss of function mutations in CCDC32 cause a congenital syndrome characterized by craniofacial, cardiac and neurodevelopmental anomalies.

No top-level findings curated for this source.

PMID:35451546

Cardiofacioneurodevelopmental syndrome: Report of a novel patient and expansion of the phenotype.

No top-level findings curated for this source.

PMID:38818818

A novel homozygous deletion in CCDC32 gene causing cardiofacioneurodevelopmental syndrome: the fourth patient reported.

No top-level findings curated for this source.

PMID:41639596

Two siblings with CCDC32-related cardiofacioneurodevelopmental syndrome diagnosed by clinical RNA-sequencing and review of literature.

No top-level findings curated for this source.

PMID:33859415

A genome-wide atlas of co-essential modules assigns function to uncharacterized genes.

No top-level findings curated for this source.

PMID:39145939

An AAGAB-to-CCDC32 handover mechanism controls the assembly of the AP2 adaptor complex.

No top-level findings curated for this source.

PMID:41489497

CCDC32 stabilizes clathrin-coated pits and drives their invagination.

No top-level findings curated for this source.

PMID:42234739

CCDC32 collaborates with the membrane to assemble the AP-2 clathrin adaptor complex.

No top-level findings curated for this source.

PMID:31104773

A Recurrent Missense Variant in AP2M1 Impairs Clathrin-Mediated Endocytosis and Causes Developmental and Epileptic Encephalopathy.

No top-level findings curated for this source.

PMID:20301365

Cardiofaciocutaneous Syndrome.

No top-level findings curated for this source.

Deep Research

1

Claude Code ▸

1. Disease Information

claude-haiku-4-5-20251001, claude-opus-5[1m] 28 citations 2026-08-01T09:53:10.150078

1. Disease Information

Overview

Cardiofacioneurodevelopmental syndrome (CFNDS) is an autosomal recessive multiple-congenital-anomaly syndrome caused by biallelic loss-of-function variants in CCDC32. Its recognized core is global developmental delay plus bilateral cleft lip and palate, with a variable constellation of craniofacial dysmorphism, congenital heart disease, hindbrain (cerebellar vermian) hypoplasia, microcephaly, digital/nail anomalies, postnatal growth restriction, and — in one individual — laterality disturbance (abdominal situs inversus with asplenia).

The MedGen/OMIM clinical definition:

"Characterized by microcephaly, midline facial defects, developmental delay, and cerebellar hypoplasia. Variable cardiac defects may be present, including atrioventricular canal and ventricular septal defects. Heterotaxy has also been reported." — MedGen UID 1721861

Abdalla et al. proposed the two-feature core:

"We describe a core phenotype comprising developmental delay and bilateral cleft lip and palate in the three individuals with CFNDS." — PMID:35451546 (verbatim, abstract)

Key identifiers

Resource	Identifier
MONDO	MONDO:0030873 (label: "Cardiofacioneurodevelopmental syndrome"; exact synonym "CFNDS")
OMIM (phenotype)	619123
OMIM (gene)	618941 (CCDC32)
MedGen	UID 1721861
UMLS	C5436852
Orphanet	No ORPHA code identified. Direct Orphanet query returned no matching entry; MONDO:0030873 carries no Orphanet xref. Flag as an ontology-coverage gap.
ICD-10	No specific code. Best fits Q87.8 (other specified congenital malformation syndromes NEC). No dedicated code assigned.
ICD-11	No specific code. Best fits LD2F.1Y / LD2F (other specified syndromes with multiple structural anomalies). Not formally assigned.
MeSH	No dedicated descriptor. Indexed under MeSH terms of the source papers: Craniofacial Abnormalities, Heart Defects, Congenital, Neurodevelopmental Disorders, Ciliopathies, Cleft Lip, Cleft Palate, Loss of Function Mutation.
GARD	Not identified.
ClinGen	Gene-disease validity curated (see §4).

Synonyms / alternative names

CFNDS (standard abbreviation)
CCDC32-related cardiofacioneurodevelopmental syndrome (usage in Albuainain et al. 2026, PMID:41639596)
CCDC32 deficiency / CCDC32-related syndrome (informal)
Historical gene alias in older literature: C15orf57-related syndrome

Provenance of information

Entirely aggregated disease-level and case-level literature. All data derive from individual published case reports and one review; there is no EHR-derived cohort, no patient registry, no natural-history study, and no biobank cohort for CFNDS. No ICEES/COHD-style co-occurrence data exist for this entity (it has no ICD code to key on).

2. Etiology

Disease causal factors

Purely monogenic and germline. CFNDS is caused by biallelic (homozygous, in all published families) loss-of-function variants in CCDC32. No environmental, infectious, or acquired etiology is known or plausible.

"Using whole exome sequencing, we identified homozygous frameshift CCDC32 variants in three affected individuals." — PMID:32307552 (verbatim, abstract)

All reported probands to date are homozygous, arising in the context of parental consanguinity in at least two of the founding families. Compound heterozygosity is theoretically expected but has not yet been reported.

Risk factors

Genetic (causal): - Biallelic CCDC32 LoF variants (frameshift, whole-gene/multi-exon deletion, nonsense) — see §4. - Carrier parents (obligate heterozygotes are unaffected; no heterozygous phenotype reported).

Non-genetic modifier of risk: - Consanguinity is the dominant epidemiological risk factor, as for essentially all ultra-rare AR disorders. Family A was a consanguineous Arab Muslim pedigree (first cousins once removed); Family B a consanguineous Iranian (Isfahan) pedigree [PMC7268788, full text]. - Founder/population endogamy may explain the apparently recurrent large deletion allele (§4).

Environmental risk factors: none identified. No toxin, teratogen, maternal exposure, occupational, dietary, or lifestyle risk factor has been implicated. Given complete genetic determinism at the causal level, none is expected.

Age / sex / family history: Disease is congenital; sex distribution is unremarkable in the tiny cohort (roughly balanced). Family history of consanguinity or an affected sib is the actionable risk signal.

Protective factors

None identified. No protective allele, modifier allele, or environmental protective factor has been reported. gnomAD contains no reported homozygous LoF individuals that would suggest incomplete penetrance or a protective background.

Gene–environment interactions

None identified. No GxE data exist for CFNDS. CTD contains no CCDC32–chemical–disease interaction of relevance to this phenotype.

Curation note / open question: Harel et al. explicitly raised genetic modifiers as a candidate explanation for the incomplete ciliopathy phenotype (absence of cystic kidney disease and polydactyly), citing possible "cis/trans genetic interactions" [PMC7268788, full text]. This is an appropriate KNOWLEDGE_GAP discussion item.

3. Phenotypes

3.1 HPO annotation set (authoritative, from HPOA)

Retrieved from the HPO API for OMIM:619123. Sole annotation source: PMID:32307552 (2 individuals). Frequencies are literal patient counts.

HP ID	Label	Freq	HPO organ system
HP:0001263	Global developmental delay	2/2	Nervous system
HP:0000252	Microcephaly	2/2	Head and neck
HP:0410030	Cleft lip	2/2	Head and neck
HP:0000175	Cleft palate	2/2	Head and neck
HP:0000411	Protruding ear	2/2	Ear
HP:0004209	Clinodactyly of the 5th finger	2/2	Limbs
HP:0008872	Feeding difficulties in infancy	2/2	Digestive
HP:0003577	Congenital onset	2/2	Clinical course
HP:0001320	Cerebellar vermis hypoplasia	1/1	Nervous system
HP:0000028	Cryptorchidism	1/1	Male-specific
HP:0006695	Atrioventricular canal defect	1/2	Cardiovascular
HP:0001629	Ventricular septal defect	1/2	Cardiovascular
HP:0001642	Pulmonic stenosis	1/2	Cardiovascular
HP:0001746	Asplenia	1/2	Cardiovascular
HP:0003363	Abdominal situs inversus	1/2	Digestive
HP:0000316	Hypertelorism	1/2	Eye
HP:0000601	Hypotelorism	1/2	Eye
HP:0000582	Upslanted palpebral fissure	1/2	Head and neck
HP:0000347	Micrognathia	1/2	Head and neck
HP:0001156	Brachydactyly	1/2	Limbs
HP:0012385	Camptodactyly	1/2	Connective tissue
HP:0008386	Aplasia/Hypoplasia of the nails	1/2	Skin, hair, nails
HP:0007477	Abnormal dermatoglyphics	1/2	Skin, hair, nails
HP:0002808	Kyphosis	1/2	Skeletal
HP:0000007	Autosomal recessive inheritance	—	Inheritance

Note the hypertelorism/hypotelorism split (1/2 each) — this is genuine phenotypic discordance between the two index patients, not an annotation error: Individual A-II-1 had hypotelorism, Individual B-II-1 had hypertelorism [PMC7268788, full text]. This is mechanistically interesting (both are midline-patterning readouts in opposite directions) and worth a curation note.

3.2 Additional phenotypes from later reports (not yet in HPOA)

Suggested HPO terms below were verified against OLS:

HP ID	Label	Source	Notes
HP:0001249	Intellectual disability	PMID:35451546	9-y-o girl, Abdalla patient
HP:0002079	Hypoplasia of the corpus callosum	PMID:35451546	"Brain imaging disclosed hypoplastic corpus callosum"
HP:0000405	Conductive hearing impairment	PMID:35451546	Bilateral
HP:0004322	Short stature	PMID:35451546
HP:0012110	Hypoplasia of the pons	PMID:32307552 (fetus A-II-2)	[full text]
HP:0001321	Cerebellar hypoplasia	PMID:41639596	Review-level phenotype statement
HP:0000286	Epicanthus	PMID:32307552	Individual B-II-1 [full text]
HP:0000752	Hyperactivity	PMID:32307552	Individual B-II-1 [full text]

Additional descriptive features from full text, without a crisply matching specific HP term, best captured as free-text preferred_term on a broader parent: stiff upper lip, vaulted palate, underdeveloped helices, broad nasal root, prominent large nose, nail clubbing, small hands and feet, abnormal cisterna magna, missing teeth (HP:0000670 Carious teeth / HP:0000668 Hypodontia — verify against the exact clinical description before assigning).

3.3 Phenotype characteristics

Type distribution: Predominantly congenital structural malformations (craniofacial, cardiac, CNS, limb) plus neurodevelopmental/behavioral features. There are no reported disease-specific laboratory abnormalities — no biomarker, no metabolic derangement, no characteristic biochemical signature. This is important: CFNDS has no biochemical diagnostic handle.

Age of onset: Congenital (HP:0003577), 2/2. Structural anomalies are present prenatally — the terminated fetus A-II-2 was ascertained on prenatal imaging with bilateral cleft lip, vermian hypoplasia, hypoplastic pons, and abnormal cisterna magna [PMC7268788, full text]. Developmental delay declares itself in infancy; feeding difficulties are an early-infancy presentation (2/2).

Severity: Variable. Structural anomalies range from lethal-in-utero-decision severity (fetus) through moderate (VSD + pulmonic stenosis, moderate motor/language delay) to comparatively mild growth findings (one patient at 80th centile height). Neurodevelopmental severity spans "moderately delayed motor and language development" to frank intellectual disability.

Progression: The malformations are static (non-progressive congenital structural defects). The neurodevelopmental phenotype is developmental, not neurodegenerative — no regression, no progressive neurological decline has been reported in any patient. Cerebellar and callosal hypoplasia are developmental (hypoplasia), not atrophic.

Frequency: See table. All frequencies are n/2 or n/6 and are not generalizable. Only DD and bilateral cleft lip/palate approach "obligate" status, and even that is a proposal from a three-patient series.

3.4 Quality-of-life impact

No CFNDS-specific QoL data exist. No EQ-5D, SF-36, PROMIS, or disease-specific PROM has been administered. The following are reasoned extrapolations from the constituent phenotypes and should be curated as such (not as CFNDS evidence):

Bilateral cleft lip/palate (2/2 → likely near-obligate): feeding difficulty in infancy, speech/resonance impairment, recurrent otitis media and conductive hearing loss, multiple staged surgeries through childhood, facial-appearance psychosocial burden. Highest-burden single feature.
Global developmental delay / ID: dominant long-term determinant of independence and caregiver burden.
Congenital heart disease (AVSD/VSD/PS): surgical morbidity; AVSD in particular carries meaningful operative and long-term valve-function burden.
Conductive hearing loss: compounds the speech impact of cleft palate.
Feeding difficulties (2/2): early-infancy nutritional and caregiver burden.
Asplenia (with heterotaxy): lifelong invasive-infection risk requiring prophylaxis — see §12/§13.

4. Genetic / Molecular Information

4.1 Causal gene

Field	Value
Symbol	CCDC32
HGNC	HGNC:28295 → CURIE `hgnc:28295` (lowercase prefix per dismech convention)
Approved name	"coiled-coil domain containing 32"
Previous symbol	C15orf57 (appears in older literature and in Abdalla 2022)
Alias	MGC20481
Locus	15q15.1
Ensembl	ENSG00000128891
NCBI Gene	90416
UniProt	Q9BV29
OMIM (gene)	618941
RefSeq	NM_052849 (HGNC canonical); NM_001080791.2 used by Harel 2020; NM_001080792.4 used by ClinVar
Locus type	gene with protein product
Protein	194-amino-acid polypeptide (isoform reported by Harel et al.); multiple transcript variants exist

⚠️ Transcript-nomenclature hazard. Published HGVS for the two founding frameshifts is on NM_001080791.2, but ClinVar reports the same alleles on NM_001080792.4 with different numbering. Curate both and note the transcript explicitly:

Family	Published (NM_001080791.2)	ClinVar (NM_001080792.4)
A	c.54dupT, p.(Thr19Tyrfs*12)	c.27dup, p.(Thr10fs)
B	c.189_190dupGG, p.(Glu64Glyfs*12)	c.162_163dup, p.(Glu55fs)

4.2 Pathogenic variants reported

#	Variant	Type	HGVS / coordinates	Zygosity	Family / origin	Reference
1	c.54dupT	Frameshift (1-bp dup)	NM_001080791.2:c.54dupT, p.(Thr19Tyrfs*12); chr15:g.40855188dupA (hg19)	Homozygous	Family A, consanguineous Arab Muslim	PMID:32307552
2	c.189_190dupGG	Frameshift (2-bp dup)	NM_001080791.2:c.189_190dupGG, p.(Glu64Glyfs*12); chr15:g.40855052dupCC	Homozygous	Family B, consanguineous Iranian (Isfahan)	PMID:32307552
3	~32.6-kb deletion	Multi-exon/whole-gene deletion	NC_000015.10:g.40529942_40562524del (ClinVar VCV001690313, Pathogenic, condition = CFNDS)	Homozygous	Abdalla patient (9-y-o female)	PMID:35451546
4	~32.6-kb deletion	Deletion	NC_000015.10:g.(40529939_40562522)del (ClinVar VCV002431643, Pathogenic, condition = CFNDS)	Homozygous	Fernandes da Rocha patient (Portugal)	PMID:38818818
5	Deletion of exons 3–4	Intragenic multi-exon deletion, detected as exon skipping on RNA-seq	Exons 3 and 4 of CCDC32	Biallelic	Two siblings, Rotterdam	PMID:41639596
6	p.Tyr157Ter	Nonsense	ClinVar VCV002580223, VUS, condition = CFNDS	Not stated	ClinVar submission	ClinVar

Verbatim support for variant 3:

"We report a 9-year-old female patient with CFNDS caused by a homozygous 32,583-bp deletion affecting CCDC32. Independent of the affected CCDC32 transcript variant this deletion likely leads to loss of the encoded protein." — PMID:35451546 (verbatim, abstract)

🔬 Novel observation worth flagging (hypothesis, needs verification): ClinVar records VCV001690313 and VCV002431643 have near-identical breakpoints (g.40529942_40562524 vs g.40529939_40562522) yet correspond to patients reported independently from different centres (Abdalla et al., Egypt/Hamburg; Fernandes da Rocha et al., Porto). This is consistent with a recurrent, likely repeat-mediated (NAHR) deletion allele at 15q15.1, or possibly a founder allele. I could not confirm the Fernandes da Rocha breakpoints directly — that paper has no abstract in PubMed and the full text is paywalled. Curate this as a KNOWLEDGE_GAP/hypothesis, not as an established fact.

Variant classification (ACMG/AMP): ClinVar carries 4 Pathogenic CFNDS-associated CCDC32 alleles (two frameshift dups, two large deletions), all with the criteria-provided or no-assertion review status — none are expert-panel reviewed. One nonsense VUS exists. There are no ClinGen variant-curation assertions for CCDC32.

Variant class distribution: exclusively loss-of-function — frameshift duplications, whole-gene/multi-exon deletions, and (VUS) nonsense. No pathogenic missense variant has been reported. This matters mechanistically: the disease is a pure LoF/hypomorph disorder, not a gain-of-function or dominant-negative one.

Allele frequency: Both founding frameshifts were:

"Absent from gnomAD, TOPMed, Geno2MP, and GME Variome" [PMC7268788, full text]

Gene-level constraint (gnomAD v4.0): pLI = 0.19, LOEUF = 0.76. Both indicate CCDC32 is tolerant of heterozygous LoF — exactly the expected signature for a recessive disease gene, and a useful reassurance that carriers are unaffected. (LOEUF 0.76 sits above the conventional <0.6 Mendelian-dominant threshold.)

Somatic vs germline: Germline only. No somatic role. COSMIC/TCGA report no recurrent driver role for CCDC32.

Functional consequence: Loss of function. Mechanistic work (§6) shows the disease-associated truncations remove the α-helical AP-2-binding region:

"Disease-causing mutations…lack the α-helix encoded by residues 78–98…defective in AP2 binding" [PMC12768407, eLife, full text] "The CCDC32 mutant was defective in binding AP2 α and σ2 when expressed at similar levels as WT" [PMC11348294, PNAS, full text] "The AP2-regulating function of CCDC32 is disrupted by a disease-causing mutation" [PMC11348294, full text]

4.3 ClinGen gene–disease validity

Field	Value
Gene	CCDC32 (HGNC:28295)
Disease	Cardiofacioneurodevelopmental syndrome (MONDO:0030873)
MOI	Autosomal recessive (AR)
Classification	MODERATE
Expert panel	Syndromic Disorders GCEP
Date	2024-10-18

This is a CGGV-citable structured assertion for dismech evidence. Note it is Moderate, not Definitive — appropriate epistemic humility for a 5-family disease. (Structured-source citation would take the form CGGV:<assertion_id>; the assertion ID must be resolved from the ClinGen CSV via just clingen-rebuild before citing.)

ClinGen dosage sensitivity: no curation exists (0 classifications) — so no CGDS citation is available.

4.4 Modifier genes

None identified. Harel et al. invoke unspecified modifiers to explain absent classical ciliopathy features, but no modifier locus has been mapped.

4.5 Epigenetic information

No data. No methylation episignature has been described for CFNDS. (This is a plausible future study — episignatures now exist for many Mendelian NDDs — and is a reasonable KNOWLEDGE_GAP.)

4.6 Chromosomal abnormalities

The pathogenic alleles include intragenic and whole-gene deletions at 15q15.1, i.e. CNVs rather than SNVs, in 3 of 5 families. Critically:

"This deletion was not detected in previous SNP array analyses and trio exome sequencing" [PMID:41639596]

No CFNDS case has been attributed to aneuploidy, translocation, inversion, or a contiguous-gene 15q15 microdeletion syndrome. Larger 15q duplications/gains overlapping CCDC32 appear in ClinVar but are unrelated pathogenic CNVs of other phenotypes.

5. Environmental Information

Environmental factors: Not applicable. No toxin, radiation, pollutant, or occupational exposure is implicated. CTD contains no relevant CCDC32–chemical–disease axis for this phenotype.
Lifestyle factors: Not applicable. No smoking, diet, exercise, or alcohol association. (Note: general periconceptional folate status modifies non-syndromic orofacial clefting risk in the population — this is not established as relevant to the syndromic, monogenic clefting in CFNDS and should not be curated as a CFNDS factor.)
Infectious agents: Not applicable. No infectious etiology or trigger.

The only non-genetic factor with real epidemiological traction is consanguinity (§2, §9), which is a population-structure variable rather than an environmental exposure.

6. Mechanism / Pathophysiology

CFNDS has a genuinely contested and rapidly evolving mechanism, which is the most scientifically interesting aspect of this entry. Two models exist; the second has largely overtaken the first in molecular support, but the first carries the developmental-phenotype evidence.

6.1 Model A — Ciliopathy (Harel et al. 2020; the original proposal)

The founding paper framed CFNDS as a ciliopathy on the basis of phenotype overlap (laterality defect, cerebellar hypoplasia, craniofacial anomalies) plus direct functional data.

Full verbatim abstract (PMID:32307552) — safe for evidence snippets:

"Despite the wide use of genomics to investigate the molecular basis of rare congenital malformations, a significant fraction of patients remains bereft of diagnosis. As part of our continuous effort to recruit and perform genomic and functional studies on such cohorts, we investigated the genetic and mechanistic cause of disease in two independent consanguineous families affected by overlapping craniofacial, cardiac, laterality and neurodevelopmental anomalies. Using whole exome sequencing, we identified homozygous frameshift CCDC32 variants in three affected individuals. Functional analysis in a zebrafish model revealed that ccdc32 depletion recapitulates the human phenotypes. Because some of the patient phenotypes overlap defects common to ciliopathies, we asked if loss of CCDC32 might contribute to the dysfunction of this organelle. Consistent with this hypothesis, we show that ccdc32 is required for normal cilia formation in zebrafish embryos and mammalian cell culture, arguing that ciliary defects are at least partially involved in the pathomechanism of this disorder."

Supporting evidence: - Kupffer's vesicle (the zebrafish left-right organizer) cilia reduced in both number (P<0.001) and length (P<0.05) in ccdc32 crispants [MODEL_ORGANISM] - Ciliogenesis impaired in mouse IMCD3 cells on siRNA knockdown: reduced % ciliated cells (P<0.01) and reduced cilium length [IN_VITRO] - Human Protein Atlas independently localizes CCDC32 to the primary cilium, centrosome, and basal body (as well as plasma membrane and microtubules) - CCDC-family precedent: CCDC39, CCDC40, CCDC103, CCDC114 all cause primary ciliary dyskinesia

Authors' own caveats (important for balanced curation):

"Some of the hallmark ciliopathy pathologies were absent from the described individuals, such as cystic renal disease and polydactyly" [full text] "Whether this molecule also performs non-ciliary roles relevant to the human pathology remain unclear" [full text]

6.2 Model B — AP-2 adaptor assembly chaperone / clathrin-mediated endocytosis (2024–2026; now the dominant molecular model)

Three independent structural/cell-biological studies since 2024 have assigned CCDC32 a precise, non-ciliary molecular function: it is a dedicated assembly chaperone for the AP-2 clathrin adaptor complex.

The assembly pathway (PNAS 2024, PMID:39145939):

AAGAB binds the AP-2 α subunit, then recruits σ2 → AAGAB:α:σ2 ternary complex
CCDC32 recognizes AAGAB:α:σ2, displacing AAGAB → α:σ2:CCDC32 template complex
The template sequentially recruits μ2, then β2
β2 binding completes AP-2 and releases CCDC32

"AP2 assembly is controlled by a handover mechanism, switching from AAGAB-based initiation complexes to CCDC32-based template complexes" [PMC11348294, full text] "In mammalian cells deficient in AAGAB or CCDC32, all AP2 subunits are degraded" [full text] "CCDC32 is a general regulator of CME" [full text]

CCDC32 directly binds α, σ2, and μ2 — but not β2 (β2 binding is what evicts it). It is selective for AP-2 and does not regulate AP-1/AP-3/AP-4 assembly.

Cellular consequences of CCDC32 loss: AP-2 subunit degradation; loss of plasma-membrane AP-2 puncta; strongly reduced transferrin-receptor endocytosis with elevated surface TfR; impaired GLUT4 internalization.

Coated-pit dynamics (eLife 2026, PMID:41489497 / PMC12768407):

"siRNA-mediated knockdown of CCDC32 leads to the accumulation of unstable flat clathrin assemblies" [full text] "CCDC32 knockdown strongly inhibited CCP invagination" [full text] "CCDC32 interacts with AP2 via the α-AD [appendage domain]" [full text]

Notably, in this system knockdown "does not affect AP2 expression level" [full text] — an apparent tension with the PNAS degradation result, likely reflecting knockdown vs knockout depth. Worth curating as a hypothesis_groups distinction rather than smoothing over.

Structural mechanism and the membrane switch (Science Advances 2026, PMID:42234739):

"CCDC32 binds to α/σ2 in a multivalent manner, using at least three (extended FxDxF, dileucine, and AH1)" [full text] "CCDC32 uses a noncanonical WAPL (Wxxϕ) motif to bind in the same location as other tyrosine-containing cargo" [full text] "In solution, CCDC32 prevents complex assembly and actively disassembles AP-2 tetramers" [full text] "The presence of PIP2–containing membrane stabilizes the final stages of assembly" [full text] "Loss of CCDC32 significantly decreases the steady-state level of all four AP-2 subunits in HeLa cells" [full text]

So CCDC32 is a cargo-mimicking, membrane-gated chaperone: it occupies the cargo-binding sites of α/σ2 and μ2 to hold AP-2 in an assembly-competent but inactive state, and PI(4,5)P₂-containing membrane acts as the molecular switch that licenses final assembly at the plasma membrane. This elegantly couples AP-2 biogenesis to its site of action.

6.3 Reconciling the two models

These are not mutually exclusive, and the most defensible curated position is that AP-2/CME dysfunction is the primary molecular lesion, with ciliary phenotypes as a plausible downstream consequence:

Clathrin-mediated endocytosis governs surface-receptor turnover, including receptors that traffic through the ciliary pocket and regulate Hedgehog/Wnt signalling — so CME failure can secondarily impair ciliogenesis and cilium-dependent signalling.
The absence of classical ciliopathy features (no cystic kidney disease, no polydactyly, no retinal degeneration reported) argues against a primary, canonical ciliopathy.
Independent genetic support for AP-2 hypofunction as a cause of exactly this phenotype spectrum: Ap2b1 (β2) null mice "survive until birth but then die shortly afterwards, the only obvious abnormality being that they have a cleft palate" [JCS review, full text]. Abdalla et al. made precisely this argument:

"Cleft palate and cardiac defects observed in mice deficient of different AP2 subunits support a CCDC32 function in the AP2 complex." — PMID:35451546 (verbatim, abstract)
AP2σ (σ2) and AP2μ (μ2) nulls are early embryonic lethal; complete AP-2 loss is embryonic lethal. CCDC32 loss is compatible with birth — consistent with CFNDS being a partial/hypomorphic AP-2 deficiency, i.e. residual AP-2 assembly persists (AAGAB-dependent, CCDC32-independent). The Sci Adv authors make this point:

"Mutation of CCDC32 does not prevent embryonic development but results in patients with craniofacial malformations" [full text]

Another reported interaction: CCDC32 binds the C-terminus of annexin A2, itself a membrane–cytoskeleton and endocytosis protein [PMC7268788, full text] — consistent with the trafficking model.

6.4 Proposed causal chain (for a dismech pathograph)

Biallelic CCDC32 LoF (frameshift / multi-exon deletion)          [MOLECULAR]
  → Loss of CCDC32 α-helix aa78–98; failure to bind AP-2 α/σ2     [MOLECULAR]
    → Failure of the AAGAB→CCDC32 handover; no α:σ2:CCDC32 template [MOLECULAR]
      → Impaired AP-2 heterotetramer assembly; AP-2 subunit degradation [MOLECULAR]
→ Destabilized, flat, non-invaginating clathrin-coated pits [CELLULAR]
  → Reduced clathrin-mediated endocytosis / receptor internalization [CELLULAR]
    ├→ Impaired ciliogenesis (reduced cilium number and length)  [CELLULAR]  (hypothesis group: ciliary)
    │    → Defective left-right organizer (Kupffer's vesicle) function [TISSUE]
    │      → Aberrant southpaw/NODAL laterality signalling
    │        → Situs inversus, asplenia, cardiac looping defect  [ORGANISM]
    ├→ Impaired cranial neural crest / facial primordium morphogenesis [TISSUE]
    │    → Failure of lip and palatal shelf fusion
    │      → Bilateral cleft lip and palate; midline facial defects [ORGANISM]
    ├→ Impaired cardiac morphogenesis (septation / AV canal)     [TISSUE]
    │    → AVSD, VSD, pulmonic stenosis                          [ORGANISM]
    └→ Impaired cerebral/cerebellar growth and midline patterning [TISSUE]
 → Microcephaly, cerebellar vermis hypoplasia, hypoplastic
   corpus callosum, hypoplastic pons
     → Global developmental delay / intellectual disability [ORGANISM]

Upstream vs downstream: The AP-2 assembly failure is unambiguously upstream. The ciliary branch is contested in its position — Harel's model places cilia upstream of laterality/cerebellar defects directly; the newer model places cilia downstream of CME failure. Curate as two hypothesis_groups on the relevant edges (e.g. ciliary_primary vs cme_primary), with the AP-2 chain as the canonical/emerging model.

6.5 Ontology term suggestions for mechanism

GO biological process / cellular component (all verified via OLS):

GO ID	Label	Use
GO:0072583	clathrin-dependent endocytosis	Core process, DECREASED
GO:0030122	AP-2 adaptor complex	CC — the assembled target
GO:0030131	clathrin adaptor complex	CC — parent
GO:0035612	AP-2 adaptor complex binding	MF — CCDC32's molecular function
GO:0030119	AP-type membrane coat adaptor complex	CC — parent
GO:0030136	clathrin-coated vesicle	CC
GO:0060271	cilium assembly	Ciliary branch, DECREASED
GO:0007368	determination of left/right symmetry	Laterality branch, DECREASED

Additional GO candidates to verify before use: protein-containing complex assembly (GO:0065003), chaperone-mediated protein complex assembly, phosphatidylinositol-4,5-bisphosphate binding, palate development, heart looping, cerebellum development.

CL cell types (verified):

CL ID	Label	Relevance
CL:0000008	migratory cranial neural crest cell	Craniofacial/cleft branch
CL:2000073	migratory cardiac neural crest cell	Cardiac outflow branch
CL:0011012	neural crest cell	Parent

Additional candidates (verify): ciliated epithelial cell, kidney collecting duct epithelial cell (the IMCD3 in-vitro model), cardiac myocyte, Purkinje cell, neuroepithelial cell.

UBERON (verified): UBERON:0004720 cerebellar vermis. Additional candidates to verify: secondary palate, upper lip, interventricular septum, atrioventricular canal, pulmonary valve, spleen, corpus callosum, pons, Kupffer's vesicle (zebrafish-specific).

CHEBI: phosphatidylinositol 4,5-bisphosphate (the membrane switch lipid) — verify the exact CHEBI ID before use.

6.6 Other mechanism dimensions

Metabolic changes: None reported. No metabolic phenotype. (Note the GLUT4 internalization defect in CCDC32-deficient cells is a cell-biological observation, not a reported clinical metabolic phenotype in patients — do not over-read it into a diabetes claim.)
Immune involvement: No primary immune mechanism. However, asplenia (1/2 in HPOA) produces functional hyposplenism with encapsulated-organism susceptibility — a secondary, anatomically-mediated immunodeficiency, clinically important (§12/§13).
Tissue damage mechanisms: Not applicable in the classical sense — CFNDS is a developmental morphogenesis disorder, not a tissue-injury disorder. There is no oxidative stress, ischemia, fibrosis, or necrosis mechanism.
Biochemical abnormalities: No enzyme deficiency, no channelopathy, no receptor defect measurable in patient fluids. The defect is a protein-complex assembly failure.
Molecular profiling: No CFNDS transcriptomic, proteomic, metabolomic, or lipidomic patient study exists. The one transcriptomic application is diagnostic, not mechanistic — clinical RNA-seq of patient cells detecting exon 3–4 skipping (PMID:41639596).
Single-cell / spatial / multi-omics: None for CFNDS. CCDC32 shows "low tissue specificity" and "low cell type specificity" in Human Protein Atlas, with mass-spec enhancement in lymphoid tissue and single-cell enhancement in fallopian tube — none of which maps onto the disease phenotype, reinforcing that the phenotype specificity comes from developmental context, not expression restriction.
Functional genomics screens: No published CRISPR/RNAi screen result specific to CFNDS. CCDC32 is not a common-essential gene in DepMap-style screens (consistent with LOEUF 0.76 and viability of KO cell lines used in the mechanism papers).

7. Anatomical Structures Affected

Organ level

Primary (directly malformed): | System | Structures | HPO/UBERON anchor | |---|---|---| | Craniofacial | Upper lip, primary and secondary palate, mandible, external ear, orbits/interorbital distance, nose | HP:0410030, HP:0000175, HP:0000347, HP:0000411 | | Central nervous | Cerebellum (vermis), pons, corpus callosum, cerebral cortex (volume — microcephaly) | HP:0001320, HP:0012110, HP:0002079, HP:0000252; UBERON:0004720 | | Cardiovascular | Atrioventricular canal, interventricular septum, pulmonary valve | HP:0006695, HP:0001629, HP:0001642 | | Skeletal / limb | Digits (5th finger, phalanges), nails, spine (kyphosis), hands/feet size | HP:0004209, HP:0001156, HP:0012385, HP:0008386, HP:0002808 | | Genitourinary | Testis (descent) | HP:0000028 |

Secondary / complication-driven: - Spleen — asplenia (HP:0001746), in the context of the laterality defect - Abdominal viscera — situs inversus (HP:0003363) - Middle ear — conductive hearing loss, mechanistically secondary to cleft palate/eustachian dysfunction (HP:0000405) - Upper GI / feeding apparatus — feeding difficulties (HP:0008872), largely secondary to cleft and neurological status - Growth axis — postnatal growth restriction / short stature (HP:0004322)

Notably spared: Kidneys (normal renal ultrasound in both index patients), eyes/retina (normal ophthalmology in both), EEG normal in individual B-II-1 [PMC7268788, full text]. The renal and retinal sparing is the key argument against classical ciliopathy.

Body systems involved: cardiovascular, nervous, musculoskeletal, digestive, integumentary (nails/dermatoglyphics), reproductive, immune (via asplenia), sensory (auditory).

Tissue and cell level

Cranial neural crest–derived mesenchyme of the frontonasal and maxillary/mandibular prominences — the presumptive lesion site for cleft lip/palate and the facial/ear/jaw dysmorphism (CL:0000008)
Cardiac neural crest and second-heart-field derivatives — outflow/septation defects (CL:2000073)
Left-right organizer ciliated epithelium (Kupffer's vesicle in fish; embryonic node in mammals) — laterality
Cerebellar and pontine neuroepithelium / rhombic lip derivatives — vermian and pontine hypoplasia
Palatal shelf epithelium and mesenchyme — fusion failure
Epithelial tissue broadly, given CME is a general epithelial/all-cell process

Subcellular level (GO cellular component)

CCDC32 and its pathway localize to: - Plasma membrane and clathrin-coated pit / clathrin-coated vesicle (GO:0030136) — the principal site of action - AP-2 adaptor complex (GO:0030122) itself - Primary cilium, centrosome, basal body — per Human Protein Atlas - Microtubules - Cytosol (site of the AAGAB/CCDC32 pre-assembly intermediates)

Localization / lateralization

Facial clefting is bilateral in the reported patients ("bilateral cleft lip and palate" is the emphasized core feature) — a midline/bilateral pattern, not unilateral.
Digital anomalies are bilateral (bilateral camptodactyly and clinodactyly of fifth fingers).
The laterality defect is, by definition, an asymmetry disorder: abdominal situs inversus with asplenia, plus abnormal cardiac looping in the zebrafish model with "bilateral or right-sided" southpaw expression replacing normal left-sided expression.

This combination — bilateral/midline structural defects plus a stochastic laterality defect — is characteristic and diagnostically useful.

8. Temporal Development

Onset

Congenital (HP:0003577), 2/2. All structural anomalies are established in embryogenesis.
Detectable prenatally: the terminated fetus (A-II-2) was identified antenatally with bilateral cleft lip, vermian hypoplasia, hypoplastic pons, and abnormal cisterna magna — establishing that CFNDS can be recognized on second-trimester ultrasound/fetal MRI in an at-risk family.
Onset pattern: chronic/static from birth. Not acute, not subacute, not insidious.
Sequence of clinical declaration: prenatal structural findings (if imaged) → neonatal cleft and cardiac diagnosis → infantile feeding difficulty (2/2) → toddler-age developmental delay → school-age intellectual disability, hearing, and growth concerns.

Progression

Disease stages: No staging system exists and none is applicable — CFNDS is not a staged/progressive disease.
Progression rate: Non-progressive. The malformations are fixed. Developmental delay evolves into a stable intellectual disability profile rather than deteriorating.
Course pattern: Static/stable with age-dependent emergence of developmental phenotypes. No episodic, relapsing-remitting, or degenerative course has been reported in any patient.
Duration: Lifelong, chronic. Not self-limited.

Patterns

Remission: Not applicable — no spontaneous remission; "treatment-induced improvement" refers only to surgical correction of individual anomalies (cleft repair, cardiac repair), not disease remission.
Critical periods:
Weeks 4–7 post-conception — lip fusion; weeks 6–12 — secondary palate fusion. These windows are already passed at diagnosis; no prenatal intervention is possible.
Weeks 3–4 — left-right axis determination and cardiac looping.
Postnatal intervention windows are the actionable ones: cleft lip repair ~3–6 months, palate repair ~9–18 months (speech-outcome critical period), cardiac repair timed to lesion (AVSD typically 3–6 months), early intervention/speech therapy from infancy, and hearing surveillance from the neonatal period because unrecognized conductive loss compounds the cleft-related speech deficit.

Longitudinal data: No natural-history study, no registry, no longitudinal cohort exists. The oldest reported patient is 9 years old. Adult outcomes for CFNDS are entirely unknown. This is arguably the single largest knowledge gap.

9. Inheritance and Population

Epidemiology

Prevalence: Not established. With ~6 living individuals reported worldwide from 5 families since 2020, the observed prevalence is far below 1 in 1,000,000.
For structured curation: measure_type: CASES_IN_LITERATURE, prevalence_class: BELOW_1_IN_1000000 (or ULTRA_RARE), population: Worldwide. Do not assign a rate_per_100000 — no denominator-based estimate exists.
Supporting statement: "CFNDS has only been described in four living individuals and one terminated fetus from four families" (PMID:41639596) — that count precedes the two siblings in the same report.
Incidence: Not established. No birth-prevalence estimate exists.
Ascertainment caveat: True prevalence is almost certainly higher than reported. Three of five families' variants are deletions, and one was missed by both SNP array and trio exome sequencing — meaning conventional diagnostic pipelines systematically under-ascertain this disease (§10).

Genetic epidemiology

Parameter	Status
Inheritance pattern	Autosomal recessive (HP:0000007). ClinGen AR, MODERATE. All published probands homozygous.
Penetrance	Appears complete in biallelic LoF homozygotes (all reported homozygotes are affected), but n is far too small to exclude reduced penetrance. Heterozygous carriers (parents) are unaffected.
Expressivity	Variable — clearly so. Compare: one patient with AVSD + situs inversus + asplenia; another with VSD + pulmonic stenosis and normal situs; the fetus with no cardiac defect at all. Hypertelorism vs hypotelorism between the two index patients. Intrafamilial variability is untested except in the sibling pair.
Genetic anticipation	Not applicable — no repeat expansion mechanism.
Germline mosaicism	Not reported. Standard AR recurrence counselling applies; no mosaicism-specific caveat documented.
Founder effects	Suspected but unproven. The near-identical ~32.6-kb deletion in two independently reported patients (§4.2) raises either a recurrent (repeat-mediated) deletion or a founder allele. Requires breakpoint-level and haplotype confirmation.
Consanguinity	Central. Both founding families were consanguineous (Arab Muslim first cousins once removed; Iranian). Homozygosity mapping was the discovery route: ~9.06 Mb ROH in Family A, 5.23 Mb ROH in Family B [full text].
Carrier frequency	Not established. No pathogenic CCDC32 allele is reported at appreciable frequency in gnomAD; the two founding frameshifts were absent from gnomAD, TOPMed, Geno2MP, and GME Variome. Carrier frequency is presumptively <1/1,000 in unselected populations, potentially higher in specific endogamous groups.

Population demographics

Reported ancestries: Arab Muslim (Israel/Palestine region), Iranian (Isfahan), Egyptian (Abdalla cohort context), Portuguese, Dutch (Rotterdam sibling pair). This is a broad, non-clustered geographic spread — no single ethnic predilection can be claimed, though ascertainment is biased toward centres with consanguineous referral populations and toward European tertiary genetics services.
Geographic distribution: No endemic region. Cases from the Middle East, North Africa, Southern Europe, and Northwestern Europe.
Variant geography: The two founding frameshifts are each private to one Middle Eastern family. The ~32.6-kb deletion allele appears in at least two unrelated Southern-European/North-African-context patients — the only candidate for a geographically structured allele.
Sex ratio: Approximately balanced in a cohort far too small to estimate (reported: female, male, female, plus the 2024 patient and sibling pair). No sex bias is expected for an autosomal recessive disorder; do not curate a sex ratio.
Age distribution of affected individuals: All reported living patients were children at the time of report (ages 3, 6, 9 years, plus the sibling pair). No adult patient has been described. This reflects the disease's recent delineation, not necessarily a survival ceiling — but it means adult phenotype and survival are unknown.

10. Diagnostics

Clinical tests

Laboratory tests: No disease-specific laboratory test exists. There is no enzyme assay, no metabolite, no biochemical marker for CFNDS. Standard labs are non-diagnostic.
The one lab investigation with real value is functional asplenia screening in patients with laterality defects: peripheral smear for Howell-Jolly bodies, correlated with abdominal imaging.
Biomarkers: None. No FDA-listed or research biomarker. Neither diagnostic, prognostic, nor monitoring biomarkers exist. (Speculatively, surface transferrin receptor levels or AP-2 subunit abundance in patient fibroblasts could serve as a functional assay — this has been demonstrated in engineered cells but never applied to a patient sample. This is a concrete, actionable research gap.)
Imaging studies (essential, high-yield):
Brain MRI — required. Detects cerebellar vermis hypoplasia (HP:0001320), hypoplastic corpus callosum (HP:0002079), hypoplastic pons (HP:0012110), abnormal cisterna magna. This is the highest-yield single imaging study.
Echocardiography — required in all patients. Detects AVSD, VSD, pulmonic stenosis, and cardiac looping/positional abnormality.
Abdominal ultrasound / cross-sectional imaging — for situs and spleen presence. Given asplenia carries life-threatening infection risk, this is not optional in a patient with any laterality clue.
Renal ultrasound — normal in reported patients, but reasonable to exclude the ciliopathy differential.
Skeletal survey / hand radiographs — brachydactyly, clinodactyly, phalangeal anomalies, kyphosis.
Fetal ultrasound / fetal MRI — for prenatal detection in at-risk pregnancies (proven effective: the A-II-2 fetus).
Functional tests: Audiometry / tympanometry — mandatory and repeated, given bilateral conductive hearing loss and cleft palate. Feeding/swallow evaluation (videofluoroscopy) for the 2/2 infantile feeding difficulty.
Electrophysiology: EEG was normal in individual B-II-1. Seizures are not a reported CFNDS feature — a useful negative that distinguishes CFNDS from the AP2M1-related developmental and epileptic encephalopathy (see differential below). ECG accompanies echocardiography.
Biopsy / pathology: No characteristic histopathology. No diagnostic biopsy exists. Nasal brush biopsy for ciliary ultrastructure/beat frequency (the PCD workup) has not been reported in CFNDS and there is no evidence of a motile-ciliary/PCD-type respiratory phenotype — do not curate a PCD-style workup as indicated.

Genetic testing — the only definitive diagnostic modality

Recommended approach, in order of yield:

Trio exome sequencing (ES) with explicit CNV calling, or preferably
Genome sequencing (GS) — better structural-variant resolution, and
RNA sequencing (RNA-seq) as a complementary second-tier test when DNA testing is negative.

The single most important practical lesson from the literature is that conventional testing fails in this disease:

"This deletion was not detected in previous SNP array analyses and trio exome sequencing" — PMID:41639596 "highlighting the complementary value of RNA-seq" — PMID:41639596

WES utility: Established — it discovered the gene ("Using whole exome sequencing, we identified homozygous frameshift CCDC32 variants," PMID:32307552). But ES alone missed a causal intragenic deletion in one family. ES must be paired with CNV analysis, and a negative ES does not exclude CFNDS.
WGS utility: Superior for the deletion alleles that constitute the majority of reported pathogenic variation (3/5 families). Preferred first-line where available.
RNA-seq: Proven diagnostic in CFNDS — exon 3–4 skipping revealed the biallelic deletion the DNA tests missed. This makes CFNDS a genuine exemplar of RNA-seq's complementary diagnostic value.
Gene panels: CCDC32 should be included on orofacial clefting, syndromic congenital heart disease, heterotaxy/laterality, cerebellar hypoplasia/pontocerebellar, and intellectual disability/multiple congenital anomaly panels. Verify inclusion before relying on a panel — as a 2020 gene with Moderate ClinGen validity, panel coverage is inconsistent.
Single-gene testing: Reasonable only for targeted familial-variant testing (carrier testing of relatives, prenatal diagnosis) once the family's variant is known. Not appropriate as a primary diagnostic given phenotypic nonspecificity.
Chromosomal microarray (CMA)/SNP array: Documented to fail — the exon 3–4 deletion escaped SNP array. CMA remains a reasonable first-tier test for MCA/DD generally, but a normal CMA does not exclude CFNDS.
Homozygosity mapping: High value in consanguineous families — it was the discovery route (9.06 Mb and 5.23 Mb ROH). Should be run alongside ES/GS in consanguineous pedigrees.
Karyotyping / FISH: No role. No CFNDS case involves a visible chromosomal rearrangement.
Mitochondrial DNA testing: Not applicable.
Repeat expansion testing: Not applicable.

Omics-based diagnostics

RNA sequencing: the one validated omics diagnostic (above).
Proteomics / metabolomics / epigenomics / liquid biopsy: No established role. No episignature. No metabolomic signature.

Clinical criteria

No standardized diagnostic criteria, no consensus guideline, no society statement exists for CFNDS. Diagnosis is molecular: biallelic pathogenic CCDC32 variants in a compatible phenotype.
Proposed clinical gestalt prompting testing (from Abdalla's core phenotype): developmental delay + bilateral cleft lip and palate, with any of — microcephaly, cerebellar vermis hypoplasia, congenital heart defect, digital/nail anomalies, laterality anomaly, postnatal growth restriction. Consanguinity substantially raises prior probability.

Differential diagnosis

Condition	Gene(s)	Distinguishing features
Cardiofaciocutaneous syndrome (CFC)	BRAF, MAP2K1/2, KRAS	AD/de novo, RASopathy; ectodermal/hair/skin findings, HCM; cleft lip/palate not typical. The critical name-confusion pitfall.
Kabuki syndrome	KMT2D, KDM6A	AD/XL; long palpebral fissures with lower-lid eversion, persistent fetal fingerpads, CHD; cleft palate common but cleft lip less so
CHARGE syndrome	CHD7	AD; coloboma, choanal atresia, semicircular canal hypoplasia, hypogonadotropic hypogonadism
22q11.2 deletion	TBX1 region	Conotruncal CHD, palatal insufficiency/cleft palate, hypocalcemia, immune deficiency; CMA-detectable
Primary ciliary dyskinesia / heterotaxy syndromes	DNAH5, DNAI1, CCDC39, CCDC40, ZIC3, etc.	Chronic sinopulmonary disease, neonatal respiratory distress, bronchiectasis — absent in CFNDS; clefting atypical
Joubert syndrome / other cerebellar-vermis ciliopathies	AHI1, CEP290, TMEM67, etc.	Molar tooth sign, oculomotor apraxia, retinal dystrophy, nephronophthisis — renal and retinal disease absent in CFNDS
Pontocerebellar hypoplasias	TSEN54, EXOSC3, etc.	Progressive microcephaly and neurodegeneration; CFNDS is static
AP2M1-related DEE	AP2M1	Same molecular pathway (AP-2/CME) but AD de novo p.Arg170Trp, dominated by epilepsy (myoclonic-atonic); no clefting, no CHD. EEG normal in CFNDS.
Oral-facial-digital syndromes	OFD1 et al.	Oral frenula, lingual hamartomas, polydactyly (absent in CFNDS)
Non-syndromic bilateral CL/P	multifactorial	Absence of DD, CHD, cerebellar anomaly, microcephaly

Screening

Newborn screening: Not applicable and not feasible — no biochemical marker. CFNDS is not on any NBS panel.
Carrier screening: CCDC32 is not on standard expanded carrier screening panels. Given the ultra-rare status, population carrier screening is not indicated. Targeted carrier testing of relatives is indicated once a family variant is known.
Cascade screening: Appropriate for at-risk relatives in a known family (siblings of probands; extended family in consanguineous pedigrees).

11. Outcome / Prognosis

Global caveat: there is no natural-history study, no survival analysis, and no adult patient reported. Everything below is either directly observed in ≤6 children or explicitly labelled as extrapolation.

Survival and mortality

5-year / 10-year survival: Not established. No survival data.
Life expectancy: Unknown. All reported living patients were alive at last report at ages 3, 6, and 9 years, plus the sibling pair. No death of a liveborn CFNDS patient has been reported.
Mortality rate / disease-specific mortality: Not established.
One pregnancy was electively terminated following prenatal detection of anomalies (fetus A-II-2) — this is a reproductive decision, not a measure of intrinsic lethality, and should not be curated as a mortality statistic.
Reasoned prognostic drivers of mortality risk (extrapolated, not CFNDS-observed): severity of the congenital heart defect (AVSD carries the greatest operative burden), and overwhelming post-splenectomy-type sepsis risk in asplenic patients — the latter is a preventable cause of death and the single most important actionable prognostic factor.

Morbidity and function

Morbidity: Substantial and multi-domain — cognitive, speech, hearing, feeding, cardiac, and surgical.
Disability outcomes: Global developmental delay in 2/2 and frank intellectual disability in the oldest reported patient (age 9). Long-term functional independence is unknown but likely to require support. No ICF-coded outcome data exist.
Quality of life: No measured QoL data. No EQ-5D/SF-36/PROMIS administration reported.

Disease course and complications

Observed and anticipated complications: - Cleft-related: feeding failure in infancy (observed 2/2, "severe feeding difficulties" in one), velopharyngeal insufficiency, speech disorder, recurrent otitis media, bilateral conductive hearing loss (observed), dental anomalies (missing teeth observed) - Cardiac: heart failure from unrepaired AVSD/VSD, right-ventricular consequences of pulmonic stenosis, operative and post-operative morbidity - Neurological: developmental delay → intellectual disability; cerebellar signs (ataxia/coordination) plausible from vermian hypoplasia but not explicitly reported; seizures not reported - Infectious: encapsulated-organism sepsis in the asplenic patient — the highest-acuity preventable complication - Growth: postnatal growth restriction/short stature in some, but not universal (one patient at 80th centile height, another at 97th) - Behavioral: hyperactivity reported in one patient

Recovery potential

Structural anomalies are surgically correctable, not spontaneously recoverable. Cleft repair and cardiac repair yield good anatomical outcomes by general paediatric standards.
Neurodevelopmental impairment is not recoverable — it is amenable to habilitation/early intervention but not to reversal.
No disease-modifying therapy exists, so there is no "with vs without treatment" survival comparison to report.

Prediction

Prognostic factors: No validated prognostic model, no prognostic biomarker, no clinical calculator exists. Reasoned (unvalidated) determinants: severity of CHD; presence of asplenia; degree of microcephaly and hindbrain hypoplasia; adequacy/timing of cleft and hearing management.
Genotype–phenotype correlation: None established. All reported variants are complete LoF (frameshift or deletion) yet produce a variable phenotype — arguing that modifiers or stochastic developmental variation, not allele severity, drive expressivity. This is a well-posed research question.

12. Treatment

There is no disease-specific, disease-modifying, or targeted therapy for CFNDS. Management is entirely symptomatic, anatomical, and habilitative, delivered by a multidisciplinary craniofacial/genetics/cardiology team. No treatment guideline exists for CFNDS specifically; care follows the guidelines for each constituent anomaly.

Pharmacotherapy

No disease-specific pharmacotherapy.
Antibiotic prophylaxis in asplenia is the one pharmacological intervention with a strong, specific indication in the subset with asplenia/heterotaxy: penicillin prophylaxis plus a low threshold for empiric treatment of febrile illness (standard asplenia protocols).
Peri-operative and heart-failure medications as dictated by the specific cardiac lesion (diuretics, afterload reduction) — lesion-directed, not disease-directed.
Pharmacogenomics: No CPIC or PharmGKB guidance applies to CCDC32. No PGx relevance identified.

Suggested NCIT annotation:

- name: Antimicrobial Prophylaxis for Asplenia
  treatment_term:
    preferred_term: Pharmacotherapy
    term: {id: NCIT:C15986, label: Pharmacotherapy}
  therapeutic_modality: SMALL_MOLECULE

Advanced therapeutics

Gene therapy: None. Not in development. No preclinical program exists. (Conceptually challenged: the pathology is established during embryogenesis and is structural — postnatal gene replacement could not correct a cleft palate or a septal defect.)
Cell therapy: None.
RNA-based therapies (ASO/siRNA/mRNA): None. Note that despite the exon 3–4 deletion, exon-skipping/splice-modulating ASO strategies are not applicable — the lesion is a genomic deletion producing loss of protein, not a correctable splice defect, and the therapeutic window is prenatal.
Targeted therapy: None. No druggable node has been proposed. (The AP-2 assembly pathway is not currently a therapeutic target for any indication.)
Immunotherapy: Not applicable.

Surgical and interventional (the principal therapeutic modality)

Intervention	Typical timing	Purpose
Cleft lip repair (cheiloplasty)	~3–6 months	Lip closure, feeding, appearance
Cleft palate repair (palatoplasty)	~9–18 months	Palatal closure; timed to speech development
Alveolar bone grafting	~8–11 years	Alveolar continuity, dental eruption
Secondary speech surgery (pharyngoplasty)	as needed	Velopharyngeal insufficiency
Cardiac surgical repair — AVSD repair, VSD closure, pulmonary valvotomy/valvuloplasty	lesion-dependent; AVSD typically 3–6 months	Hemodynamic correction
Tympanostomy tube placement	as needed, often at cleft repair	Middle-ear effusion, conductive hearing loss
Orchidopexy	6–18 months	Cryptorchidism
Gastrostomy	if feeding failure severe	Nutrition
Orthopedic/spinal management	as needed	Kyphosis

Suggested NCIT annotations (verified via OLS unless noted):

- name: Cleft Palate Repair
  treatment_term:
    preferred_term: palatorrhaphy
    term: {id: NCIT:C168380, label: Palatorrhaphy}
  therapeutic_modality: SURGERY

- name: Congenital Heart Defect Surgical Repair
  treatment_term:
    preferred_term: surgical procedure
    term: {id: NCIT:C15329, label: Surgical Procedure}   # safe, reachable from NCIT:C25218
  therapeutic_modality: SURGERY

⚠️ NCIT:C157806 "Cardiac Surgery" also exists but may sit outside the NCIT:C25218 (Clinical Intervention or Procedure) subtree used by the dismech TreatmentTerm dynamic enum — validate with just validate-terms before using it; NCIT:C15329 is the safe fallback.

Supportive and rehabilitative

Intervention	NCIT	Modality
Speech and language therapy — high priority (cleft + DD + hearing)	NCIT:C159273	BEHAVIORAL
Physical therapy	NCIT:C15302	BEHAVIORAL
Occupational therapy	NCIT:C121351	BEHAVIORAL
Nutritional/feeding support	NCIT:C15433 (Nutritional Support) — see CLAUDE.md caution on modality tagging	—
Supportive care (general)	NCIT:C15747	—
Genetic counseling	NCIT:C15240	—
Hearing amplification / hearing aids	No suitable NCIT clinical-action term — omit `term:`, keep free-text `preferred_term`; `therapeutic_modality: DEVICE`	DEVICE
Developmental early intervention / special education	NCIT:C15315 (Rehabilitation)	BEHAVIORAL

Experimental treatments

No clinical trials exist for CFNDS. A ClinicalTrials.gov search yields no interventional or observational study recruiting CFNDS or CCDC32 patients. No NCT identifiers to report. Do not curate a clinical_trials: block for this entry.

Treatment outcomes

Response rates: No CFNDS-specific outcome data. Outcomes of cleft repair and CHD repair in CFNDS patients have not been separately reported.
Side effects / adverse events: No disease-specific pharmacovigilance signal (no disease-specific drug). Surgical risks are the standard risks of the respective procedures.

Treatment strategy

Algorithm: No CFNDS-specific pathway. Practical approach: (1) confirm molecular diagnosis; (2) complete the baseline evaluation — echocardiogram, brain MRI, abdominal imaging for situs/spleen, audiology, ophthalmology, renal ultrasound, feeding assessment, developmental assessment; (3) refer to a multidisciplinary craniofacial team; (4) stage cleft and cardiac surgery per standard protocols; (5) institute early intervention and hearing surveillance; (6) if asplenic, start antibiotic prophylaxis and asplenia vaccination immediately; (7) genetic counselling for the family.
Combination therapies: Not applicable in the pharmacological sense; management is inherently multimodal/multidisciplinary.
Personalized/genotype-guided treatment: None available. No genotype-guided management stratification exists — and with all reported alleles being complete LoF, none is currently plausible.

13. Prevention

Prevention levels

Primary prevention (preventing occurrence): The only effective primary prevention is reproductive — genetic counselling, carrier testing, and reproductive options in at-risk (typically consanguineous) families. There is no modifiable exposure to target. Population-level consanguinity counselling programs reduce the aggregate burden of AR disease but are not CFNDS-specific.
Secondary prevention (early detection): Prenatal ultrasound/fetal MRI in at-risk pregnancies is proven to detect the phenotype (fetus A-II-2). Targeted prenatal molecular testing (CVS/amniocentesis for the known familial variant) is definitive. Postnatally, early molecular diagnosis enables timely baseline evaluation.
Tertiary prevention (preventing complications in affected individuals) — this is where the highest-value, concrete actions lie:
Asplenia protocol: lifelong antibiotic prophylaxis + immunization + fever action plan. Prevents the most likely preventable death.
Audiology surveillance from birth: prevents hearing loss compounding speech/language deficit.
Timely palatoplasty within the speech-critical window: prevents durable velopharyngeal speech impairment.
Cardiac surveillance and timely repair: prevents pulmonary vascular disease and heart failure.
Feeding/nutrition management: prevents failure to thrive.
Early developmental intervention: optimizes attainable function.

Immunization

Highly relevant in the asplenic subset. Standard functional-asplenia immunization: pneumococcal (conjugate + polysaccharide), meningococcal (ACWY and B), and Haemophilus influenzae type b, plus annual influenza. Otherwise, routine childhood immunization per national schedule.

Suggested annotation: treatment_term: NCIT:C15346 (Vaccination), therapeutic_modality: VACCINE.

Screening and early detection

Population screening programs: None applicable. Not newborn-screenable (no biochemical marker); too rare for population carrier screening.
Genetic screening in families: Carrier testing of at-risk relatives; preimplantation genetic testing for monogenic disease (PGT-M) and prenatal diagnosis (CVS/amniocentesis) are both technically available once the familial variant is characterized. For families whose variant is a deletion, ensure the prenatal assay is deletion-capable (targeted MLPA/ddPCR or breakpoint-spanning PCR — a standard variant-specific Sanger assay will fail).
Risk stratification: Prior risk is driven by consanguinity and by an affected sibling (1 in 4 recurrence).

Behavioral interventions

Not applicable to disease occurrence. Standard periconceptional care (folic acid, avoidance of teratogens) is appropriate general practice but has no established effect on CFNDS risk and should not be curated as a CFNDS protective factor.

Counseling

Genetic counselling is the cornerstone of prevention. Content should include: - Autosomal recessive inheritance; 25% recurrence risk for each pregnancy of carrier parents - Carrier parents are unaffected (supported by gnomAD constraint: pLI 0.19, LOEUF 0.76) - Extended-family carrier risk in consanguineous pedigrees; offer cascade testing - Availability of PGT-M and prenatal diagnosis - Honest communication of prognostic uncertainty — with ~6 published patients and no adult data, families must be told that long-term outcome is genuinely unknown - Consanguinity counselling for the wider kindred where culturally appropriate

NCIT: NCIT:C15240 Genetic Counseling.

Public health / environmental interventions

Not applicable. No environmental determinant. The only population-level lever is consanguinity-related genetic services and premarital/preconception carrier screening programs in high-consanguinity populations — a general AR-disease intervention, not CFNDS-specific.

Prophylaxis

Antibiotic prophylaxis for asplenia — the one strongly indicated prophylactic medication (see above).
Endocarditis prophylaxis per standard cardiology guidelines for the specific repaired/unrepaired cardiac lesion.

14. Other Species / Natural Disease

Taxonomy of species with relevant biology

Species	NCBI Taxon	Relevance
Homo sapiens	NCBITaxon:9606	The only species with naturally occurring CFNDS
Danio rerio (zebrafish)	NCBITaxon:7955	Principal experimental model (§15)
Mus musculus (mouse)	NCBITaxon:10090	Cell-line source (IMCD3); no published whole-animal Ccdc32 model

Breed

Not applicable. No breed-associated CFNDS-equivalent disorder has been described. No VBO identifiers apply.

Orthologous genes

Zebrafish ccdc32: a single ortholog, with 46% amino-acid identity and 64% similarity to human CCDC32 [PMC7268788, full text]. Modest conservation, but functionally sufficient — depletion recapitulates the human phenotype.
Mouse Ccdc32: ortholog exists (used for the IMCD3 siRNA experiments, targeted via siCcdc32). MGI record exists; I could not retrieve an IMPC phenotype page (404), and no IMPC null-allele phenotype data were located.
Human NCBI Gene ID 90416 is the anchor for ortholog lookup (Alliance of Genome Resources / HomoloGene).

Natural disease in other species

None known. No OMIA entry, no veterinary case series, no spontaneous animal disorder corresponding to CFNDS has been reported. There is no companion-animal or wildlife counterpart, and no veterinary health importance.

Comparative biology

Evolutionary conservation of mechanism: Strong. Harel et al. concluded that "CCDC32 plays an evolutionarily conserved role in cilia formation in the vertebrate left/right organizing center" [full text]. The AP-2 adaptor complex and its assembly chaperones (AAGAB, CCDC32) are deeply conserved across eukaryotes, and the AP-2 assembly mechanism described in human cells is expected to be broadly conserved.
Comparative pathology — concordances: zebrafish ccdc32 crispants reproduce reduced head size (≈ microcephaly), altered facial cartilage morphology (≈ craniofacial dysmorphism/clefting), cerebellar hypoplasia, disrupted cardiac looping, and laterality randomization (≈ situs inversus).
Comparative pathology — divergences: the zebrafish model shows no global developmental delay (normal body length), and clefting per se cannot be modelled in fish (no secondary palate) — only the homologous pharyngeal cartilage patterning.

Transmission

Not applicable. CFNDS is a germline monogenic disorder. No zoonotic potential, no cross-species transmission, no infectious component.

15. Model Organisms

15.1 Zebrafish (Danio rerio, NCBITaxon:7955) — the primary and best-characterized model

Model type: vertebrate, mammalian-adjacent developmental model; F0 CRISPR crispant (mosaic knockout).

Construction: Two distinct sgRNAs (sgRNA1, sgRNA2) targeting non-overlapping regions of exon 2, injected with Cas9 protein at the one-cell stage. Editing efficiency: 85% (sgRNA1) and 70% (sgRNA2) mosaic alterations in F0 crispants [PMC7268788, full text]. Two independent guides is good practice and substantially strengthens the specificity of the result.

Expression pattern in zebrafish: ccdc32 detected as early as 1 hour post-fertilization; localized to the developing head and neural tube throughout embryogenesis, and particularly concentrated in the Kupffer's vesicle region — a spatial pattern that closely prefigures the human phenotype (head, CNS, laterality).

Phenotypes observed [all MODEL_ORGANISM evidence]:

Zebrafish phenotype	Human counterpart	Statistics
Significant reduction in head size at 3 dpf	Microcephaly (HP:0000252)	Significant vs uninjected and sgRNA-only controls
Altered facial cartilage morphology (ceratohyal angle)	Craniofacial dysmorphism / clefting	P < 0.05
Hypoplastic cerebellum (anti-α-acetylated tubulin)	Cerebellar vermis hypoplasia (HP:0001320)	Qualitative + morphometric
Disrupted cardiac looping at 2 dpf (normal/midline/reversed)	Cardiac malformation, looping abnormality	Both sgRNAs
Aberrant *southpaw (spaw)* expression at 18-somite stage — bilateral or right-sided instead of left	Situs inversus, asplenia (HP:0003363, HP:0001746)	Qualitative scoring
Kupffer's vesicle cilia reduced in number and length at 10-somite stage	Ciliary mechanism hypothesis	Number P<0.001; length P<0.05; one-way ANOVA + Tukey
Normal body length	—	Explicitly noted: no global developmental delay

"ccdc32 depletion recapitulates the human phenotypes" — PMID:32307552 (verbatim, abstract)

Phenotype recapitulation quality: Good for craniofacial, cerebellar, cardiac-looping, and laterality domains. This is a genuinely convergent model — four independent human phenotype domains reproduced.

Limitations: - F0 crispants are mosaic, not stable germline nulls — a stable mutant line has not been reported and is an obvious next step. - Cleft lip/palate cannot be modelled — zebrafish have no secondary palate; only homologous pharyngeal cartilage patterning is assessable. - Intellectual disability/global developmental delay cannot be modelled; body length was explicitly normal. - Situs inversus and asplenia are assessed indirectly (spaw expression, cardiac looping) rather than as terminal organ situs. - Crispant phenotypes can carry p53-dependent off-target/toxicity artefacts; the two-independent-guide design mitigates but does not eliminate this. - Modest human–fish protein identity (46%) limits inference about specific residues/motifs.

Resource: ZFIN (the ZFIN publication record ZDB-PUB-220423-8 exists for the Abdalla paper; I was unable to retrieve the ccdc32 gene record — ZFIN returned a CAPTCHA/traffic page — so the ZFIN gene ID should be looked up before curation).

15.2 Mammalian cell models

mIMCD3 5-HT6-GFP (mouse inner medullary collecting duct, ciliated reporter line) [IN_VITRO] - siRNA against Ccdc32 (5 nM) vs non-targeting control; 24 h serum starvation to induce ciliogenesis; knockdown validated by qRT-PCR with three primer sets - Result: significantly reduced % ciliated cells (P<0.01) and reduced cilium length (P<0.05 to P<0.001) - Rigor: >500 cells per replicate, 4 replicates, >1000 cilia measured, imaging blinded to condition — a well-controlled experiment

"Cilia formation is similarly impaired in ciliated mouse inner medullary collecting duct cells" [full text]

HeLa and other human cell lines (2024–2026 mechanism studies) [IN_VITRO] - CCDC32 knockout HeLa cells: loss of all four AP-2 subunits at steady state; loss of plasma-membrane AP-2 puncta; strongly reduced transferrin-receptor endocytosis with elevated surface TfR; impaired GLUT4 internalization - siRNA knockdown: accumulation of unstable flat clathrin assemblies; inhibited CCP invagination; reduced TfnR uptake - Structure–function: deletion constructs (e.g. CCDC32(1-54), mimicking the patient truncations) fail to rescue CCP stabilization; patient-mutant CCDC32 is defective in binding AP-2 α and σ2 — this is the closest thing to a direct functional validation of patient alleles - In vitro reconstitution with PIP2-containing liposomes — the membrane-switch experiments (Sci Adv 2026)

Patient-derived cells: None reported beyond the RNA-seq performed on patient material for diagnosis (PMID:41639596). No patient fibroblast, iPSC, organoid, or neuronal model of CFNDS exists. This is a major and readily addressable gap.

15.3 Mouse (Mus musculus, NCBITaxon:10090)

No published Ccdc32 whole-animal knockout or knock-in mouse model exists. I found no IMPC phenotype data (the queried IMPC gene page returned 404) and no MGI-recorded allele phenotype for a Ccdc32 null.
A commercially available conditional (flox) allele exists — a Ccdc32-flox C57BL/6 line (Cyagen Ccdc32em1flox) is catalogued — but no phenotype has been published from it. Curate as "resource available, phenotype unpublished," not as a characterized model.
Highly informative surrogate models — the AP-2 subunit knockouts:
Ap2b1 (β2) null: "mice lacking the single-copy AP-2 β subunit gene AP2B1 survive until birth but then die shortly afterwards, the only obvious abnormality being that they have a cleft palate" [JCS review, full text] — strikingly convergent with the CFNDS core phenotype. Survival is attributed to partial redundancy with the AP-1 β paralog.
Ap2s1 (σ2) null: early embryonic lethal (~E3.5–E9.5).
Ap2m1 (μ2) null: early embryonic lethal.
Complete AP-2 loss: "Complete loss of AP-2 is early embryonic lethal" [JCS review, full text]
Interpretive value: these establish a dosage/severity gradient in which CFNDS sits at the mild, viable end — consistent with CCDC32 loss producing partial rather than complete AP-2 deficiency, and directly supporting the cleft palate and cardiac phenotypes as AP-2-attributable. ⚠️ Do not conflate the AP-2 adaptor complex α subunit (AP2A1/AP2A2) with the AP-2α transcription factor (TFAP2A) — searches readily mix them, and TFAP2A knockouts also produce cleft palate and cardiovascular defects for entirely unrelated reasons.

15.4 Applications and gaps

What current models support: ciliogenesis assays; left-right patterning; craniofacial cartilage morphometry; cardiac looping; AP-2 assembly biochemistry and structural biology; CCP dynamics by TIRF; transferrin-uptake functional readouts; direct testing of patient alleles in rescue assays.

What no current model supports: the neurodevelopmental/cognitive phenotype; cleft lip and palate morphogenesis in a mammal; longitudinal/adult natural history; therapeutic testing.

Highest-value next models: (1) a stable germline zebrafish ccdc32 mutant line; (2) a constitutive or neural-crest-conditional mouse Ccdc32 knockout using the existing flox allele — with explicit assessment of palate, cardiac septation, situs, and brain; (3) patient-derived iPSC neural crest cells and cerebral/cardiac organoids; (4) patient fibroblast AP-2 abundance and transferrin-uptake assays as a candidate functional diagnostic for VUS resolution.

Model databases: ZFIN (zebrafish), MGI / IMPC / IMSR / KOMP (mouse), Alliance of Genome Resources (ortholog integration), Cellosaurus (HeLa, mIMCD3 lines).

Appendix A — Consolidated Reference List

PMID	Citation	Type	Role
32307552	Harel T, Griffin JN, Arbogast T, Monroe TO, Palombo F, Martinelli M, Seri M, Pippucci T, Elpeleg O, Katsanis N. Loss of function mutations in CCDC32 cause a congenital syndrome characterized by craniofacial, cardiac and neurodevelopmental anomalies. Hum Mol Genet. 2020;29(9):1489-1497. DOI 10.1093/hmg/ddaa073. PMC7268788	HUMAN_CLINICAL + MODEL_ORGANISM + IN_VITRO	Founding paper. Gene discovery, 2 families/3 individuals, zebrafish, ciliary model. Sole HPOA annotation source.
35451546	Abdalla E, Alawi M, Meinecke P, Kutsche K, Harms FL. Cardiofacioneurodevelopmental syndrome: Report of a novel patient and expansion of the phenotype. Am J Med Genet A. 2022;188(8):2448-2453. DOI 10.1002/ajmg.a.62762	HUMAN_CLINICAL	3rd patient; defines the core phenotype; first to propose the AP-2 link.
38818818	Fernandes da Rocha D, Quental R, Grangeia A, Pinto Moura C. A novel homozygous deletion in CCDC32 gene causing cardiofacioneurodevelopmental syndrome: the fourth patient reported. Clin Dysmorphol. 2024;33(3):114-117. DOI 10.1097/MCD.0000000000000501	HUMAN_CLINICAL	4th patient. ⚠️ No abstract in PubMed; full text paywalled — no quotable snippet obtainable.
41639596	Albuainain F, Venema M, Schot R, Huigen G, Mancini GMS, van Ham TJ, Barakat TS. Two siblings with CCDC32-related cardiofacioneurodevelopmental syndrome diagnosed by clinical RNA-sequencing and review of literature. Eur J Hum Genet. 2026. DOI 10.1038/s41431-026-02023-y. PMC13046869	HUMAN_CLINICAL	Most recent + only review. Sibling pair; RNA-seq diagnosis; literature synthesis. ⚠️ Full text not retrievable (403/paywall) — the feature-by-feature review table could not be extracted.
39145939	Wan C, Puscher H, Ouyang Y, Wu J, Tian Y, Li S, Yin Q, Shen J. An AAGAB-to-CCDC32 handover mechanism controls the assembly of the AP2 adaptor complex. PNAS. 2024. PMC11348294	IN_VITRO	Defines CCDC32's molecular function. Tests a CFNDS patient mutant.
41489497	Yang Z, Yang C, Huang Z, Xu P, Li Y, Han L, Peng L, Wei X, Pak JE, Svitkina T, Schmid SL, Chen Z. CCDC32 stabilizes clathrin-coated pits and drives their invagination. eLife. 2026. PMC12768407 (preprint: PMID 38979322)	IN_VITRO	CCP dynamics; maps the aa78-98 α-helix removed by disease alleles.
42234739	Sloan DE, Matthews AE, Yanagisawa H, Tedamrongwanish T, Cannon K, Simmons J, Chappell G, Nicely NI, Berlow R, Kikkawa M, Baker RW. CCDC32 collaborates with the membrane to assemble the AP-2 clathrin adaptor complex. Sci Adv. 2026. PMC13267310 (preprint: PMID 40799577)	IN_VITRO / structural	Structural mechanism; PIP2 membrane as molecular switch.
39250673	Stepwise assembly of the AP2 endocytic clathrin adaptor complex. PNAS. 2024. PMC11420168	Commentary	Contextual commentary on the assembly pathway.
—	Sanger JM et al. Adaptor protein complexes and disease at a glance. J Cell Sci. 2019;132(20):jcs222992	Review	AP-2 subunit KO phenotypes; AP2S1/AP2M1 human disease.

Structured / database sources: MONDO:0030873 (OLS/EBI); MedGen UID 1721861; HPO API annotations for OMIM:619123; HGNC:28295; ClinGen gene-disease validity (Syndromic Disorders GCEP, 2024-10-18, MODERATE); ClinVar (VCV001690313, VCV002431643, VCV000988600, VCV000988601, VCV002580223); gnomAD v4.0 constraint; Human Protein Atlas ENSG00000128891.

Appendix B — Explicit "No Data" Register

For honest curation, these are confirmed absences, not unsearched areas:

Domain	Status
Orphanet entry / ORPHA code	Not found — ontology coverage gap
ICD-10 / ICD-11 specific code	None assigned
Dedicated MeSH descriptor	None
GARD entry	Not identified
Prevalence / incidence estimate	None — literature case count only
Natural history study, registry, longitudinal cohort	None
Adult patient reported	None — oldest is 9 years
Survival / mortality data	None
QoL instrument data (EQ-5D/SF-36/PROMIS)	None
Diagnostic criteria / consensus guideline / society statement	None
Biomarker (diagnostic, prognostic, monitoring)	None
Prognostic model or genotype-phenotype correlation	None
Clinical trials (ClinicalTrials.gov)	None
Disease-modifying / targeted / gene / RNA therapy	None; none in development
Pharmacogenomics (CPIC/PharmGKB)	Not applicable
Methylation episignature	None
Patient transcriptomics/proteomics/metabolomics (mechanistic)	None (RNA-seq used diagnostically only)
Patient-derived fibroblast / iPSC / organoid model	None
Published mouse model phenotype	None (flox allele commercially available, unpublished)
IMPC data for Ccdc32	Not found
Naturally occurring disease in other species / OMIA entry	None
Environmental, infectious, lifestyle, or GxE factor	None; not applicable
ClinGen dosage sensitivity / variant / actionability curation	None (validity curation only)
Newborn or population carrier screening	Not applicable / not indicated

Appendix C — Suggested High-Priority `discussions` Entries for the KB Record

kind: KNOWLEDGE_GAP — Adult phenotype, survival, and natural history are entirely unknown (oldest reported patient age 9).
kind: KNOWLEDGE_GAP — Are the two ~32.6-kb deletions (ClinVar VCV001690313 / VCV002431643) the same recurrent, repeat-mediated allele? Breakpoint and haplotype analysis needed. Proposed experiment: breakpoint-junction sequencing and SNP-haplotype comparison across reported deletion carriers.
kind: HUMAN_MODEL_MISMATCH — The zebrafish ccdc32 crispant supports a primary ciliary mechanism, but the 2024–2026 human-cell structural/biochemical work assigns CCDC32 a primary AP-2 assembly function, and patients lack the cardinal ciliopathy features (cystic kidney disease, polydactyly, retinal dystrophy). Whether the ciliary defect is primary or secondary to CME failure is unresolved. Proposed experiments: test ciliogenesis in CCDC32-KO human cells with AP-2 rescue; assay ciliary receptor trafficking; characterize a stable zebrafish mutant line and a neural-crest-conditional mouse KO.
kind: KNOWLEDGE_GAP — All reported alleles are complete LoF yet expressivity is markedly variable (hypertelorism vs hypotelorism; AVSD+heterotaxy vs isolated VSD; fetus with no cardiac defect). Modifiers, stochastic developmental variation, or both?
kind: KNOWLEDGE_GAP — No functional assay exists to classify CCDC32 VUS (e.g. the p.Tyr157Ter ClinVar VUS). Proposed experiment: validate patient-fibroblast AP-2 subunit abundance and transferrin-uptake as a clinical-grade functional readout.

Suggested conforms_to candidates: none of the existing dismech modules is a clean fit. pharyngeal_arch_patterning_serial_homology is a partial conceptual neighbour (cranial-neural-crest-derived multi-element craniofacial malformation) but CFNDS's lesion is a trafficking/assembly chaperone rather than an arch-patterning or ribosome/spliceosome lesion, and the CFNDS bundle is not confined to arch derivatives — do not force conformance. If a module is created, the natural one is a new "AP-2 adaptor assembly / clathrin-mediated endocytosis deficiency" module, which would already have three worked conformers across the pathway (CCDC32→CFNDS, AP2M1→DEE, AP2S1→FHH3, AAGAB→punctate PPK type 1) — a genuinely reusable conserved mechanism.

Sources: - OMIM #619123 — CARDIOFACIONEURODEVELOPMENTAL SYNDROME; CFNDS - OMIM *618941 — CCDC32 - Harel et al. 2020, Hum Mol Genet (PMID:32307552) · full text PMC7268788 · publisher - Abdalla et al. 2022, Am J Med Genet A (PMID:35451546) · Wiley - Fernandes da Rocha et al. 2024, Clin Dysmorphol (PMID:38818818) · journal - Albuainain et al. 2026, Eur J Hum Genet (PMID:41639596) - Wan et al. 2024, PNAS — AAGAB-to-CCDC32 handover (PMC11348294) - Yang et al. 2026, eLife — CCDC32 stabilizes clathrin-coated pits (PMC12768407) - Sloan et al. 2026, Sci Adv — CCDC32 collaborates with the membrane (PMC13267310) - Stepwise assembly of the AP2 endocytic clathrin adaptor complex, PNAS 2024 (PMC11420168) - Adaptor protein complexes and disease at a glance, J Cell Sci 2019 - MedGen UID 1721861 — CFNDS - HPO annotations for OMIM:619123 - MONDO:0030873 via EBI OLS4 - HGNC:28295 — CCDC32 - ClinGen curation results for CCDC32 (HGNC:28295) - ClinVar — CCDC32 variants - gnomAD v4.0 gene constraint - Human Protein Atlas — CCDC32 (ENSG00000128891) - GeneCards — CCDC32 - Cyagen Ccdc32-flox mouse model - AAGAB mutations in punctate palmoplantar keratoderma (PMC4282079) - Mutations in AP2S1 cause familial hypocalciuric hypercalcemia type 3, Nat Genet - Modeling AP2M1 developmental and epileptic encephalopathy in Drosophila, DMM

Ask OpenScientist

OpenScientist Report

Classifications

Inheritance

Mechanistic Hypotheses

Discussions and Knowledge Gaps

Pathophysiology

Pathograph

Phenotypes

Genetic Associations

Medical Actions

Differential Diagnoses

Source YAML

References & Deep Research

References

Deep Research

1. Disease Information

Overview

Key identifiers

Synonyms / alternative names

Provenance of information

2. Etiology

Disease causal factors

Risk factors

Protective factors

Gene–environment interactions

3. Phenotypes

3.1 HPO annotation set (authoritative, from HPOA)

3.2 Additional phenotypes from later reports (not yet in HPOA)

3.3 Phenotype characteristics

3.4 Quality-of-life impact

4. Genetic / Molecular Information

4.1 Causal gene

4.2 Pathogenic variants reported

4.3 ClinGen gene–disease validity

4.4 Modifier genes

4.5 Epigenetic information

4.6 Chromosomal abnormalities

5. Environmental Information

6. Mechanism / Pathophysiology

6.1 Model A — Ciliopathy (Harel et al. 2020; the original proposal)

6.2 Model B — AP-2 adaptor assembly chaperone / clathrin-mediated endocytosis (2024–2026; now the dominant molecular model)

6.3 Reconciling the two models

6.4 Proposed causal chain (for a dismech pathograph)

6.5 Ontology term suggestions for mechanism

6.6 Other mechanism dimensions

7. Anatomical Structures Affected

Organ level

Tissue and cell level

Subcellular level (GO cellular component)

Localization / lateralization

8. Temporal Development

Onset

Progression

Patterns

9. Inheritance and Population

Epidemiology

Genetic epidemiology

Population demographics

10. Diagnostics

Clinical tests

Genetic testing — the only definitive diagnostic modality

Omics-based diagnostics

Clinical criteria

Differential diagnosis

Screening

11. Outcome / Prognosis

Survival and mortality

Morbidity and function

Disease course and complications

Recovery potential

Prediction

12. Treatment

Pharmacotherapy

Advanced therapeutics

Surgical and interventional (the principal therapeutic modality)

Supportive and rehabilitative

Experimental treatments

Treatment outcomes

Treatment strategy

Appendix C — Suggested High-Priority `discussions` Entries for the KB Record