STIL

Chr 1AR

STIL centriolar assembly protein

Also known as: MCPH7, SIL

NCBI Gene: 6491 ENSG00000123473 UniProt: Q15468

This gene encodes a cytoplasmic protein implicated in regulation of the mitotic spindle checkpoint, a regulatory pathway that monitors chromosome segregation during cell division to ensure the proper distribution of chromosomes to daughter cells. The protein is phosphorylated in mitosis and in response to activation of the spindle checkpoint, and disappears when cells transition to G1 phase. It interacts with a mitotic regulator, and its expression is required to efficiently activate the spindle checkpoint. It is proposed to regulate Cdc2 kinase activity during spindle checkpoint arrest. Chromosomal deletions that fuse this gene and the adjacent locus commonly occur in T cell leukemias, and are thought to arise through illegitimate V-(D)-J recombination events. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

Primary Disease Associations & Inheritance

Microcephaly 7, primary, autosomal recessiveMIM #612703

470

ClinVar variants

Pathogenic / LP

0.20

pLI score

Active trials

Clinical Summary— STIL

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Gene-Disease Validity (ClinGen)

autosomal recessive primary microcephaly · ARDefinitive

Definitive — sufficient evidence for diagnostic panels

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Population Constraint (gnomAD)

Constrained for loss-of-function variants (OE-LoF 0.24) despite low pLI — interpret in context.

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ClinVar Variants

38 Pathogenic / Likely Pathogenic· 256 VUS of 470 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.

0.38LOEUF

pLI 0.201

Z-score 5.04

OE 0.24 (0.15–0.38)

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.

1.13Z-score

OE missense 0.88 (0.82–0.94)

587 obs / 668.9 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.0.24 (0.15–0.38)

0≤0.351.4

Missense OE?Ratio of observed to expected missense variants. OE ≤ 0.6 = fewer missense variants than expected by chance.0.88 (0.82–0.94)

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.0.87

0≤1.21.6

LoF obs/exp: 12 / 50.8Missense obs/exp: 587 / 668.9Syn Z: 1.54