FAT4

Chr 4AR

FAT atypical cadherin 4

Also known as: CDHF14, CDHR11, FAT-J, FATJ, HKLLS2, NBLA00548, VMLDS2

FAT4 encodes a protocadherin that maintains planar cell polarity and regulates cell adhesion and proliferation. Mutations cause autosomal recessive Hennekam lymphangiectasia-lymphedema syndrome 2 and Van Maldergem syndrome 2, affecting lymphatic development, growth, and facial features. The gene is highly constrained against loss-of-function variants (pLI ~1.0, LOEUF 0.18), indicating strong selective pressure for proper function.

GeneReviewsOMIMResearchSummary from RefSeq, OMIM, UniProt
LOFmechanismARLOEUF 0.182 OMIM phenotypes
Clinical SummaryFAT4
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Gene-Disease Validity (ClinGen)
FAT4-related neurodevelopmental disorder · ARDefinitive

Definitive — sufficient evidence for diagnostic panels

Population Constraint (gnomAD)
Highly constrained gene — heterozygous loss-of-function variants are very rare in the population (pLI 1.00). One damaged copy is likely sufficient to cause disease.
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ClinVar Variants
1 unique Pathogenic / Likely Pathogenic· 28 VUS of 100 total submissions
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GeneReview available — FAT4
Authoritative clinical overview · Recommended first read
Open GeneReview ↗

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

LoF intolerant — likely haploinsufficient
LoF Constraint
0.18LOEUF
pLI 1.000
Z-score 9.37
OE 0.12 (0.080.18)
Highly constrained

Highly LoF-intolerant (top ~10% of genes)

Missense Constraint
0.62Z-score
OE missense 0.97 (0.931.00)
2545 obs / 2634.8 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios
LoF OE0.12 (0.080.18)
00.351.4
Missense OE0.97 (0.931.00)
00.61.4
Synonymous OE1.05
01.21.6
LoF obs/exp: 16 / 132.3Missense obs/exp: 2545 / 2634.8Syn Z: -1.30
Curated Mechanism (G2P)Gene2Phenotype (DDG2P) ↗
definitiveFAT4-related Hennekam lymphangiectasia-lymphedema syndromeOTHERAR
definitiveFAT4-related Van Maldergem syndromeLOFAR

Predictions shown for reference only — model trained on dominant genes, not applicable to AR conditions.

DN
0.4586th %ile
GOF
0.4283th %ile
LOF
0.67top 25%

The Badonyi & Marsh prediction model was trained exclusively on dominant disease genes. Predictions are not reliable for genes with autosomal recessive inheritance and are shown at reduced opacity for reference only.

Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312. Mechanism ranking also informed by gnomAD constraint, ClinVar, and ClinGen data.

ClinVar Variant Classifications

100 submitted variants in ClinVar

Classification Summary

Pathogenic1
VUS28
Likely Benign70
Conflicting1
1
Pathogenic
28
VUS
70
Likely Benign
1
Conflicting

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

ClassificationLoFMissense + InframeNon-codingSynonymousTotal
Pathogenic
1
0
0
0
1
Likely Pathogenic
0
0
0
0
0
VUS
2
25
1
0
28
Likely Benign
0
0
10
60
70
Benign
0
0
0
0
0
Conflicting
1
Total3251160100

LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly

View in ClinVar →

Protein Context — Lollipop Plot

FAT4 · protein map & ClinVar variants

Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.

3D Protein StructureAlphaFold

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

No active trials found for this gene.

Search ClinicalTrials.gov →
Clinical Literature
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