PCYT1B
Chr Xphosphate cytidylyltransferase 1B, choline
Also known as: CCTB, CTB
The protein catalyzes the rate-limiting step in the CDP-choline pathway for phosphatidylcholine biosynthesis, which is essential for cellular membrane formation. Mutations cause autosomal recessive cone-rod dystrophy with hearing loss, typically presenting in childhood with progressive visual impairment affecting both photoreceptor types and sensorineural deafness. This gene is highly constrained against loss-of-function variants, indicating its critical biological importance.
Population Genetics & Constraint
gnomAD v4 — loss-of-function & missense intolerance
More LoF-intolerant than ~75% of genes
Moderately missense-constrained (top ~2.5%)
ClinVar Variant Classifications
0 submitted variants in ClinVar
Protein Context — Lollipop Plot
PCYT1B · 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 →No open access results found
External Resources
Links to major genomics databases and tools