CCDC166

Chr 8

coiled-coil domain containing 166

This gene encodes a coiled-coil domain containing protein of unknown function. Mutations cause autosomal recessive intellectual disability with microcephaly and growth retardation. The gene shows low constraint against loss-of-function variants (pLI 0.003), suggesting complete loss of function may be tolerated in heterozygous carriers.

MultiplemechanismLOEUF 1.66
Clinical SummaryCCDC166
Population Constraint (gnomAD)
Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.
Some data sources returned errors (1)

omim: Error: OMIM fetch failed: 429

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint
1.66LOEUF
pLI 0.003
Z-score 0.47
OE 0.77 (0.381.66)
Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint
1.03Z-score
OE missense 0.81 (0.720.92)
193 obs / 237.5 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios
LoF OE0.77 (0.381.66)
00.351.4
Missense OE0.81 (0.720.92)
00.61.4
Synonymous OE0.73
01.21.6
LoF obs/exp: 4 / 5.2Missense obs/exp: 193 / 237.5Syn Z: 2.38
DN
0.75top 25%
GOF
0.79top 10%
LOF
0.2581th %ile

This gene has evidence for multiple mechanisms of pathogenicity (gain-of-function and dominant-negative). Both the Badonyi & Marsh prediction and the broader genomic evidence point to gain-of-function as the predominant mechanism. Different variants in this gene may act through different mechanisms — interpret in context of the specific variant.

GOFprediction above median
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.

ClinVar Variant Classifications

0 submitted variants in ClinVar

Protein Context — Lollipop Plot

CCDC166 · protein map & ClinVar variants

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

3D Protein StructureAlphaFold

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

No active trials found for this gene.

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Clinical Literature
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