CPB2
Chr 13carboxypeptidase B2
Also known as: CPU, PCPB, TAFI
The protein encoded by CPB2 is a carboxypeptidase that cleaves C-terminal arginine and lysine residues from bioactive peptides and downregulates fibrinolysis by removing C-terminal lysine residues from partially degraded fibrin. Mutations cause carboxypeptidase B2 deficiency, which presents as increased bleeding tendency due to impaired regulation of fibrinolysis, inherited in an autosomal recessive pattern. The gene shows very low constraint against loss-of-function variants (pLI near zero), consistent with recessive inheritance.
Population Genetics & Constraint
gnomAD v4 — loss-of-function & missense intolerance
Highly tolerant — LoF variants common in population
Mild missense constraint
The highest-scoring mechanism for this gene is dominant-negative.
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
116 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 | 54 | 0 | 54 |
Likely Pathogenic | 0 | 0 | 1 | 0 | 1 |
VUS | 1 | 35 | 1 | 0 | 37 |
Likely Benign | 0 | 5 | 1 | 5 | 11 |
Benign | 0 | 2 | 0 | 5 | 7 |
| Total | 1 | 42 | 57 | 10 | 110 |
LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly
View in ClinVar →Protein Context — Lollipop Plot
CPB2 · 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
External Resources
Links to major genomics databases and tools