PCYT1B

Chr X

phosphate cytidylyltransferase 1B, choline

Also known as: CCTB, CTB

NCBI Gene: 9468ENSG00000102230UniProt: Q9Y5K3

The protein encoded by this gene belongs to the cytidylyltransferase family. It is involved in the regulation of phosphatidylcholine biosynthesis. Several alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Sep 2009]

96
ClinVar variants
62
Pathogenic / LP
0.90
pLI score
0
Active trials
Clinical Summary— PCYT1B
⚡
Population Constraint (gnomAD)
Moderately constrained gene (pLI 0.90) — some intolerance to loss-of-function variants.
📋
ClinVar Variants
62 Pathogenic / Likely Pathogenic· 31 VUS of 96 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.
0.40LOEUF
pLI 0.897
Z-score 2.91
OE 0.09 (0.03–0.40)
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.
2.16Z-score
OE missense 0.48 (0.39–0.59)
65 obs / 135.8 exp
Mild constraint

Moderately missense-constrained (top ~2.5%)

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.0.09 (0.03–0.40)
0≤0.351.4
Missense OE?Ratio of observed to expected missense variants. OE ≤ 0.6 = fewer missense variants than expected by chance.0.48 (0.39–0.59)
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.1.09
0≤1.21.6
LoF obs/exp: 1 / 11.8Missense obs/exp: 65 / 135.8Syn Z: -0.50

ClinVar Variant Classifications

96 submitted variants in ClinVar

ClinVar

Classification Summary

Pathogenic62
VUS31
Likely Benign3
62
Pathogenic
31
VUS
3
Likely Benign

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

ClassificationLoFMissense + InframeNon-codingSynonymousTotal
Pathogenic
0
0
62
0
62
Likely Pathogenic
0
0
0
0
0
VUS
0
16
15
0
31
Likely Benign
0
0
1
2
3
Benign
0
0
0
0
0
Total01678296

LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly

View 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.

OMIM — Genotype-Phenotype Relationships

1 OMIM entry

OMIM
Clinical Literature
Landmark / reviewRecent case evidence
Key Publications
Landmark & review papers · by relevance
PubMed
Top 10 resultsSearch PubMed ↗
Recent Gene-Specific Literature
Gene in title · MEDLINE · newest first
Europe PMC
Top 5 resultsSearch Europe PMC ↗

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

ClinicalTrials.gov

No active trials found for this gene.

Search ClinicalTrials.gov →

External Resources

Links to major genomics databases and tools