FAT1

Chr 4

FAT atypical cadherin 1

Also known as: CDHF7, CDHR8, FAT, ME5, hFat1

NCBI Gene: 2195 ENSG00000083857 UniProt: Q14517

This gene is an ortholog of the Drosophila fat gene, which encodes a tumor suppressor essential for controlling cell proliferation during Drosophila development. The gene product is a member of the cadherin superfamily, a group of integral membrane proteins characterized by the presence of cadherin-type repeats. In addition to containing 34 tandem cadherin-type repeats, the gene product has five epidermal growth factor (EGF)-like repeats and one laminin A-G domain. This gene is expressed at high levels in a number of fetal epithelia. Its product probably functions as an adhesion molecule and/or signaling receptor, and is likely to be important in developmental processes and cell communication. Transcript variants derived from alternative splicing and/or alternative promoter usage exist, but they have not been fully described. [provided by RefSeq, Jul 2008]

Active trials

Pathogenic / LP

438

ClinVar variants

Pubs (1 yr)

-0.4

Missense Z

0.43

LOEUF

Clinical Summary— FAT1

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Gene-Disease Validity (ClinGen)

focal segmental glomerulosclerosis · ARStrong

Strong evidence — appropriate for clinical testing

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Population Constraint (gnomAD)

Constrained for loss-of-function variants (OE-LoF 0.34) despite low pLI — interpret in context.

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ClinVar Variants

19 Pathogenic / Likely Pathogenic· 307 VUS of 438 total submissions

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Clinical Trials

4 active or recruiting trials — potential therapeutic options may be available

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

gnomAD

Moderate LoF intolerance

LoF Constraint?LOEUF (Loss-of-function Observed/Expected Upper bound Fraction) is the upper bound of the 90% CI for LoF OE — the preferred gnomAD v4 metric. Lower = more intolerant to LoF. LOEUF < 0.35 = highly constrained.

0.43LOEUF

pLI 0.000

Z-score 7.35

OE 0.34 (0.27–0.43)

Moderately constrained

More LoF-intolerant than ~75% of genes

Missense Constraint?Missense Z-score: standard deviations fewer missense variants observed vs. expected. Z > 3.09 (p < 0.001) = gene does not tolerate missense variation. OE missense < 0.6 is also considered constrained.

-0.43Z-score

OE missense 1.02 (0.99–1.06)

2611 obs / 2549.8 exp

Tolerant

Tolerant to missense variation

Observed / Expected Ratios?Shaded band = 90% confidence interval. Vertical tick = point estimate. Grey threshold line = gnomAD constraint cutoff for that variant class.

LoF OE?Ratio of observed to expected LoF variants. Upper CI bound (LOEUF) ≤ 0.35 = strong LoF constraint signal.0.34 (0.27–0.43)

0≤0.351.4

Missense OE?Ratio of observed to expected missense variants. OE ≤ 0.6 = fewer missense variants than expected by chance.1.02 (0.99–1.06)

0≤0.61.4

Synonymous OE?Control metric — synonymous variants are largely neutral and expected near OE = 1.0. Significant deviation may indicate annotation issues.1.08

0≤1.21.6

LoF obs/exp: 49 / 144.2Missense obs/exp: 2611 / 2549.8Syn Z: -2.04

0.6936th %ile

GOF

0.6053th %ile

LOF

0.3940th %ile

This gene has evidence for multiple mechanisms of pathogenicity (dominant-negative and loss-of-function). Both the Badonyi & Marsh prediction and the broader genomic evidence point to dominant-negative as the predominant mechanism. Different variants in this gene may act through different mechanisms — interpret in context of the specific variant.

DNprediction above median

LOF63% of P/LP variants are LoF · LOEUF 0.43

Note: In-silico variant effect predictors (SIFT, PolyPhen, REVEL, CADD) may underestimate pathogenicity of missense variants in genes with GOF or DN mechanisms. Consider functional evidence and clinical context.

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