BTD
Chr 3ARbiotinidase
Biotinidase recycles protein-bound biotin by cleaving biocytin to regenerate free biotin and also functions as a biotinyl transferase. Mutations cause biotinidase deficiency, an autosomal recessive disorder that impairs biotin recycling and can lead to metabolic dysfunction. Loss-of-function mutations result in reduced enzyme activity, preventing adequate biotin availability for essential carboxylase enzymes.
Moderate evidence — consider for supplementary testing
2 total gene-disease associations curated
Population Genetics & Constraint
gnomAD v4 — loss-of-function & missense intolerance
Highly tolerant — LoF variants common in population
Tolerant to missense variation
ClinVar Variant Classifications
400 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 | 12 | 8 | 12 | 0 | 32 |
Likely Pathogenic | 26 | 20 | 1 | 0 | 47 |
VUS | 1 | 201 | 19 | 0 | 221 |
Likely Benign | 0 | 2 | 19 | 35 | 56 |
Benign | 1 | 0 | 5 | 0 | 6 |
Conflicting | — | 7 | |||
| Total | 40 | 231 | 56 | 35 | 369 |
LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly
View in ClinVar →Protein Context — Lollipop Plot
BTD · 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