CCDC178

Chr 18

coiled-coil domain containing 178

Also known as: C18orf34

CCDC178 encodes a protein located in the ciliary basal body that plays a crucial role in head shaping and sperm flagellum formation. Mutations cause autosomal recessive disorders affecting craniofacial development and ciliary function. The gene shows minimal constraint against loss-of-function variants, consistent with recessive inheritance patterns.

OMIMResearchSummary from RefSeq, UniProt
MultiplemechanismLOEUF 1.12
Clinical SummaryCCDC178
Population Constraint (gnomAD)
Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint
1.12LOEUF
pLI 0.000
Z-score 0.90
OE 0.86 (0.661.12)
Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint
-0.55Z-score
OE missense 1.08 (0.991.17)
423 obs / 392.5 exp
Tolerant

Tolerant to missense variation

Observed / Expected Ratios
LoF OE0.86 (0.661.12)
00.351.4
Missense OE1.08 (0.991.17)
00.61.4
Synonymous OE0.81
01.21.6
LoF obs/exp: 39 / 45.6Missense obs/exp: 423 / 392.5Syn Z: 1.75
DN
0.6453th %ile
GOF
0.75top 25%
LOF
0.3453th %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

CCDC178 · 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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