GUCA1C
Chr 3guanylate cyclase activator 1C
Also known as: GCAP3
The protein functions as a calcium-sensitive regulator of guanylyl cyclases in rod photoreceptors, stimulating these enzymes at low calcium concentrations and inhibiting them at high calcium concentrations to enable recovery of the dark state following light exposure. Mutations cause autosomal recessive cone-rod dystrophy, a retinal degeneration affecting both cone and rod photoreceptors. This gene shows low constraint against loss-of-function variants, consistent with recessive inheritance where both copies must be affected to cause disease.
Population Genetics & Constraint
gnomAD v4 — loss-of-function & missense intolerance
Highly tolerant — LoF variants common in population
Tolerant to missense variation
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.
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
68 submitted variants in ClinVar
Classification Summary
Curated Variants Distribution
Classified variants from ClinVar · 5 ACMG categories
| Classification | LoF | Missense + Inframe | Non-coding | Synonymous | Total |
|---|---|---|---|---|---|
Pathogenic | 0 | 0 | 16 | 0 | 16 |
Likely Pathogenic | 0 | 0 | 0 | 0 | 0 |
VUS | 0 | 32 | 6 | 0 | 38 |
Likely Benign | 0 | 3 | 3 | 0 | 6 |
Benign | 0 | 0 | 0 | 0 | 0 |
| Total | 0 | 35 | 25 | 0 | 60 |
LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly
View in ClinVar →Protein Context — Lollipop Plot
GUCA1C · protein map & ClinVar variants
Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.
3D Protein StructureAlphaFold
External Resources
Links to major genomics databases and tools
Clinical Trials
Active and recruiting trials from ClinicalTrials.gov
No active trials found for this gene.
Search ClinicalTrials.gov →External Resources
Links to major genomics databases and tools