FAM78A

Chr 9

family with sequence similarity 78 member A

Also known as: C9orf59

NCBI Gene: 286336 ENSG00000126882 UniProt: Q5JUQ0

Active trials

Pathogenic / LP

ClinVar variants

Pubs (1 yr)

1.8

Missense Z

0.70

LOEUF

Clinical Summary— FAM78A

⚡

Population Constraint (gnomAD)

Constrained for loss-of-function variants (OE-LoF 0.22) despite low pLI — interpret in context.

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

gnomAD

Tolerant — LoF & missense variants common in population

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.

0.70LOEUF

pLI 0.373

Z-score 2.17

OE 0.22 (0.09–0.70)

Tolerant

Typical tolerance to LoF variation

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.

1.80Z-score

OE missense 0.64 (0.55–0.74)

124 obs / 194.9 exp

Tolerant

Mild missense constraint

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.0.22 (0.09–0.70)

0≤0.351.4

Missense OE?Ratio of observed to expected missense variants. OE ≤ 0.6 = fewer missense variants than expected by chance.0.64 (0.55–0.74)

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.0.97

0≤1.21.6

LoF obs/exp: 2 / 9.0Missense obs/exp: 124 / 194.9Syn Z: 0.22

0.4587th %ile

GOF

0.73top 25%

LOF

0.49top 25%

The highest-scoring mechanism for this gene is gain-of-function.

GOFprediction above median

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.