KIFC3

Chr 16

kinesin family member C3

NCBI Gene: 3801 ENSG00000140859 UniProt: Q9BVG8

This gene encodes a member of the kinesin-14 family of microtubule motors. Members of this family play a role in the formation, maintenance and remodeling of the bipolar mitotic spindle. The protein encoded by this gene has cytoplasmic functions in the interphase cells. It may also be involved in the final stages of cytokinesis. Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Jan 2016]

Active trials

Pathogenic / LP

145

ClinVar variants

Pubs (1 yr)

2.0

Missense Z

0.46

LOEUF

Clinical Summary— KIFC3

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Population Constraint (gnomAD)

Constrained for loss-of-function variants (OE-LoF 0.29) despite low pLI — interpret in context.

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ClinVar Variants

21 Pathogenic / Likely Pathogenic· 122 VUS of 145 total submissions

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.

0.46LOEUF

pLI 0.006

Z-score 4.42

OE 0.29 (0.19–0.46)

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.

1.99Z-score

OE missense 0.76 (0.70–0.82)

399 obs / 527.8 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.0.29 (0.19–0.46)

0≤0.351.4

Missense OE?Ratio of observed to expected missense variants. OE ≤ 0.6 = fewer missense variants than expected by chance.0.76 (0.70–0.82)

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.0.93

0≤1.21.6

LoF obs/exp: 13 / 45.0Missense obs/exp: 399 / 527.8Syn Z: 0.88

0.77top 25%

GOF

0.6832th %ile

LOF

0.3259th %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.