KIFAP3

Chr 1

kinesin associated protein 3

Also known as: FLA3, KAP-1, KAP-3, KAP3, SMAP, Smg-GDS, dJ190I16.1

The small G protein GDP dissociation stimulator (smg GDS) is a regulator protein having two activities on a group of small G proteins including the Rho and Rap1 family members and Ki-Ras; one is to stimulate their GDP/GTP exchange reactions, and the other is to inhibit their interactions with membranes. The protein encoded by this gene contains 9 'Armadillo' repeats and interacts with the smg GDS protein through these repeats. This protein, which is highly concentrated around the endoplasmic reticulum, is phosphorylated by v-src, and this phosphorylation reduces the affinity of the protein for smg GDS. It is thought that this protein serves as a linker between human chromosome-associated polypeptide (HCAP) and KIF3A/B, a kinesin superfamily protein in the nucleus, and that it plays a role in the interaction of chromosomes with an ATPase motor protein. Several transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Mar 2011]

ResearchGenerating clinical summary…
MultiplemechanismLOEUF 0.54
Clinical SummaryKIFAP3
Population Constraint (gnomAD)
Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.
📋
ClinVar Variants
64 VUS of 97 total submissions
Some data sources returned errors (1)

omim: Error: OMIM fetch failed: 429

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Moderate LoF intolerance
LoF Constraint?
0.54LOEUF
pLI 0.000
Z-score 4.05
OE 0.36 (0.250.54)
Moderately constrained

More LoF-intolerant than ~75% of genes

Missense Constraint?
1.91Z-score
OE missense 0.73 (0.670.81)
295 obs / 402.9 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios?
LoF OE?0.36 (0.250.54)
00.351.4
Missense OE?0.73 (0.670.81)
00.61.4
Synonymous OE?1.09
01.21.6
LoF obs/exp: 17 / 46.9Missense obs/exp: 295 / 402.9Syn Z: -0.86

This gene — mechanism propensity

DN
0.7033th %ile
GOF
0.7029th %ile
LOF
0.3356th %ile

This gene has evidence for multiple mechanisms of pathogenicity (dominant-negative and gain-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
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.

ClinVar Variant Classifications

97 submitted variants in ClinVar

Classification Summary

VUS64
Likely Benign4
Benign4
64
VUS
4
Likely Benign
4
Benign

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

ClassificationLoFMissense + InframeNon-codingSynonymousTotal
Pathogenic
0
0
0
0
0
Likely Pathogenic
0
0
0
0
0
VUS
1
63
0
0
64
Likely Benign
0
1
0
3
4
Benign
0
2
0
2
4
Total1660572

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

View in ClinVar →

24 pathogenic / likely-pathogenic (of 25) ClinVar copy-number / structural variants overlap KIFAP3 — these span large chromosomal regions, not the gene specifically, and are excluded from the counts above. Explore in CNV tools →

Protein Context — Lollipop Plot

KIFAP3 · protein map & ClinVar variants

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

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

No active trials found for this gene.

Search ClinicalTrials.gov →