GKAP1

Chr 9

G kinase anchoring protein 1

Also known as: FKSG21, GKAP42

NCBI Gene: 80318 ENSG00000165113 UniProt: Q5VSY0

This gene encodes a protein that is highly similar to the mouse cGMP-dependent protein kinase anchoring protein 42kDa. The mouse protein has been found to localize with the Golgi and recruit cGMP-dependent protein kinase I alpha to the Golgi in mouse testes. It is thought to play a role in germ cell development. Transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Oct 2008]

Active trials

Pathogenic / LP

ClinVar variants

Pubs (1 yr)

0.7

Missense Z

0.52

LOEUF

Clinical Summary— GKAP1

⚡

Population Constraint (gnomAD)

Constrained for loss-of-function variants (OE-LoF 0.28) despite low pLI — interpret in context.

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.

0.52LOEUF

pLI 0.061

Z-score 3.35

OE 0.28 (0.16–0.52)

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.

0.73Z-score

OE missense 0.84 (0.74–0.97)

146 obs / 173.1 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.0.28 (0.16–0.52)

0≤0.351.4

Missense OE?Ratio of observed to expected missense variants. OE ≤ 0.6 = fewer missense variants than expected by chance.0.84 (0.74–0.97)

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: 7 / 25.1Missense obs/exp: 146 / 173.1Syn Z: -0.49

0.6936th %ile

GOF

0.5169th %ile

LOF

0.3841th %ile

The highest-scoring mechanism for this gene is dominant-negative.

DNprediction 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.