CSTB
Chr 21ARcystatin B
Also known as: CPI-B, CST6, EPM1, EPM1A, PME, STFB, ULD
CSTB encodes cystatin B, an intracellular thiol protease inhibitor that reversibly inhibits cathepsins L, H, and B, protecting cells against proteases that leak from lysosomes. Mutations cause Unverricht-Lundborg disease (progressive myoclonic epilepsy type 1A), a childhood-onset progressive myoclonic epilepsy inherited in an autosomal recessive pattern. The gene shows low constraint against loss-of-function variants (pLI 0.007, LOEUF 1.85), consistent with its recessive inheritance pattern.
Definitive — sufficient evidence for diagnostic panels
2 total gene-disease associations curated
Population Genetics & Constraint
gnomAD v4 — loss-of-function & missense intolerance
Highly tolerant — LoF variants common in population
Mild missense constraint
Predictions shown for reference only — model trained on dominant genes, not applicable to AR conditions.
The Badonyi & Marsh prediction model was trained exclusively on dominant disease genes. Predictions are not reliable for genes with autosomal recessive inheritance and are shown at reduced opacity for reference only.
Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.
ClinVar Variant Classifications
0 submitted variants in ClinVar
Protein Context — Lollipop Plot
CSTB · 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