Biotinidase deficiency: genes and variants
Explore variant evidence for Biotinidase deficiency across 1 analyzed protein (BTD). Linked ClinVar records include 87 pathogenic or likely pathogenic variants, 99 variants of uncertain significance and 57 with conflicting classifications.
Coverage includes proteins already analyzed in CATVariant, not every gene involved in this condition. Database links are associations, not an assessment of clinical gene–disease validity. Computable evidence prioritizes variants for expert review and does not reclassify them. Counts refer to the selected disease label.
Data updated 2026-10-11. Automated aggregation, not a clinical review date.
Download variant evidence (CSV)
Genes linked to Biotinidase deficiency
BTD: Biotinidase
Biotinidase recycles biotin from biocytin and dietary proteins so cells can reuse this vitamin. Deficiency is treatable with biotin supplementation.
87 ClinVar pathogenic / likely pathogenic and 156 uncertain variants in BTD have source records linked to Biotinidase deficiency. Association strength is not clinical gene validity.
ClinVar pathogenic and likely pathogenic variants linked to Biotinidase deficiency
| Variant | Position | Protein part | Clinical label |
|---|---|---|---|
| BTD E92K | 92 | CN hydrolase | Pathogenic / likely pathogenic (★★) |
| BTD E92Q | 92 | CN hydrolase | Pathogenic / likely pathogenic (★★) |
| BTD C140Y | 140 | CN hydrolase | Pathogenic / likely pathogenic (★★) |
| BTD C140F | 140 | CN hydrolase | Pathogenic / likely pathogenic (★★) |
| BTD A142V | 142 | CN hydrolase | Pathogenic / likely pathogenic (★★) |
| BTD N175D | 175 | CN hydrolase | Pathogenic / likely pathogenic (★★) |
| BTD I228T | 228 | CN hydrolase | Pathogenic / likely pathogenic (★★) |
| BTD L258P | 258 | CN hydrolase | Pathogenic / likely pathogenic (★★) |
| BTD C404S | 404 | Pathogenic / likely pathogenic (★★) | |
| BTD V42M | 42 | Pathogenic / likely pathogenic (★★) | |
| BTD C166G | 166 | CN hydrolase | Pathogenic / likely pathogenic (★★) |
| BTD C166Y | 166 | CN hydrolase | Pathogenic / likely pathogenic (★★) |
| BTD L258V | 258 | CN hydrolase | Pathogenic / likely pathogenic (★★) |
| BTD C404Y | 404 | Pathogenic / likely pathogenic (★★) | |
| BTD D424Y | 424 | Pathogenic / likely pathogenic (★★) | |
| BTD Y434C | 434 | Pathogenic / likely pathogenic (★★) | |
| BTD R518H | 518 | Pathogenic / likely pathogenic (★★) | |
| BTD R518S | 518 | Pathogenic / likely pathogenic (★★) | |
| BTD R59C | 59 | CN hydrolase | Pathogenic / likely pathogenic (★★) |
| BTD F174L | 174 | CN hydrolase | Pathogenic / likely pathogenic (★★) |
| BTD Y190C | 190 | CN hydrolase | Pathogenic / likely pathogenic (★★) |
| BTD T214I | 214 | CN hydrolase | Pathogenic / likely pathogenic (★★) |
| BTD I235T | 235 | CN hydrolase | Pathogenic / likely pathogenic (★★) |
| BTD C398S | 398 | Pathogenic / likely pathogenic (★★) | |
| BTD C398R | 398 | Pathogenic / likely pathogenic (★★) | |
| BTD C403R | 403 | Pathogenic / likely pathogenic (★★) | |
| BTD D424H | 424 | Pathogenic / likely pathogenic (★★) | |
| BTD H427Y | 427 | Pathogenic / likely pathogenic (★★) | |
| BTD Y520C | 520 | Pathogenic / likely pathogenic (★★) | |
| BTD R137C | 137 | CN hydrolase | Pathogenic / likely pathogenic (★★) |
| BTD L195F | 195 | CN hydrolase | Pathogenic / likely pathogenic (★★) |
| BTD C225Y | 225 | CN hydrolase | Pathogenic / likely pathogenic (★★) |
| BTD P233L | 233 | CN hydrolase | Pathogenic / likely pathogenic (★★) |
| BTD A269V | 269 | CN hydrolase | Pathogenic / likely pathogenic (★★) |
| BTD S291N | 291 | CN hydrolase | Pathogenic / likely pathogenic (★★) |
| BTD P477S | 477 | Pathogenic / likely pathogenic (★★) | |
| BTD L20P | 20 | Pathogenic / likely pathogenic (★★) | |
| BTD R59H | 59 | CN hydrolase | Pathogenic / likely pathogenic (★★) |
| BTD Y73C | 73 | CN hydrolase | Pathogenic / likely pathogenic (★★) |
| BTD E198D | 198 | CN hydrolase | Pathogenic / likely pathogenic (★★) |
| BTD A279P | 279 | CN hydrolase | Pathogenic / likely pathogenic (★★) |
| BTD L385P | 385 | Pathogenic / likely pathogenic (★★) | |
| BTD Y418C | 418 | Pathogenic / likely pathogenic (★★) | |
| BTD A458P | 458 | Pathogenic / likely pathogenic (★★) | |
| BTD A151T | 151 | CN hydrolase | Pathogenic / likely pathogenic (★★) |
| BTD V179M | 179 | CN hydrolase | Pathogenic / likely pathogenic (★★) |
| BTD R189H | 189 | CN hydrolase | Pathogenic / likely pathogenic (★★) |
| BTD D232G | 232 | CN hydrolase | Pathogenic / likely pathogenic (★★) |
| BTD N469S | 469 | Pathogenic / likely pathogenic (★★) | |
| BTD D523E | 523 | Pathogenic / likely pathogenic (★★) | |
| BTD G14S | 14 | Pathogenic / likely pathogenic (★★) | |
| BTD A419D | 419 | Pathogenic / likely pathogenic (★★) | |
| BTD H465Q | 465 | Pathogenic / likely pathogenic (★★) | |
| BTD N175S | 175 | CN hydrolase | Pathogenic / likely pathogenic (★) |
| BTD G292V | 292 | CN hydrolase | Pathogenic / likely pathogenic (★) |
| BTD G292S | 292 | CN hydrolase | Pathogenic / likely pathogenic (★) |
| BTD Y434D | 434 | Pathogenic / likely pathogenic (★) | |
| BTD V42A | 42 | Pathogenic / likely pathogenic (★) | |
| BTD A142P | 142 | CN hydrolase | Pathogenic / likely pathogenic (★) |
| BTD C166R | 166 | CN hydrolase | Pathogenic / likely pathogenic (★) |
Showing 60 of 87.
Uncertain variants prioritized for review in Biotinidase deficiency
| Variant | Position | Protein part | Clinical label | Evidence |
|---|---|---|---|---|
| BTD R518L | 518 | Conflicting reports (★) | +7: 4 other pathogenic changes within 3 positions; R518H at the same position is pathogenic; seen in 6.9e-07 of gnomAD DNA copies; REVEL 0.961 | |
| BTD G292D | 292 | CN hydrolase | Conflicting reports (★) | +7: 5 other pathogenic changes within 3 positions; G292V at the same position is pathogenic; seen in 6.6e-06 of gnomAD DNA copies; REVEL 0.924 |
| BTD Y418H | 418 | Conflicting reports (★) | +7: 2 other pathogenic changes within 3 positions; Y418C at the same position is pathogenic; seen in 6.6e-06 of gnomAD DNA copies; REVEL 0.927 | |
| BTD P233S | 233 | CN hydrolase | Conflicting reports (★) | +7: 4 other pathogenic changes within 3 positions; P233L at the same position is pathogenic; seen in 6.6e-06 of gnomAD DNA copies; REVEL 0.810 |
| BTD G425V | 425 | Conflicting reports (★) | +7: 5 other pathogenic changes within 3 positions; G425E at the same position is pathogenic; seen in 6.6e-06 of gnomAD DNA copies; REVEL 0.834 | |
| BTD V437L | 437 | Conflicting reports (★) | +7: 3 other pathogenic changes within 3 positions; V437M at the same position is pathogenic; seen in 6.6e-06 of gnomAD DNA copies; REVEL 0.792 | |
| BTD E44D | 44 | Conflicting reports (★) | +6: 3 other pathogenic changes within 3 positions; E44K at the same position is pathogenic; not seen in the gnomAD population database; AlphaMissense 0.92 | |
| BTD D523V | 523 | Conflicting reports (★) | +6: 2 other pathogenic changes within 3 positions; D523E at the same position is pathogenic; REVEL 0.832 | |
| BTD C166W | 166 | CN hydrolase | Uncertain (★) | +6: 3 other pathogenic changes within 3 positions; C166G at the same position is pathogenic; not seen in the gnomAD population database; AlphaMissense 0.91 |
Diseases related to Biotinidase deficiency
- Fetal anomalies with a likely genetic cause, also linked to BTD
- Possible mitochondrial disorder - nuclear genes, also linked to BTD
Frequently asked questions
Which genes have records linked to Biotinidase deficiency?
This view contains 1 analyzed proteins: BTD. Links come from clinical records and association databases. They do not imply that every listed gene is a validated cause, and missing genes may not yet be analyzed.
What do the clinical classifications mean?
Linked records include 87 pathogenic or likely pathogenic variants, 99 variants of uncertain significance and 57 with conflicting classifications. Labels summarize source records; multi-condition records may not make a separate assertion for this disease. Check the original record and review status.
Does the evidence score change a VUS classification?
No. 9 VUS or conflicting variants reach the likely-pathogenic points range on the computable criteria available here. This is a research prioritization signal, not a clinical classification. Patient, family and other required evidence may be missing.
Can I download the variant evidence?
Download the CSV for all 318 variants in the selected disease scope, including clinical labels, review status, evidence criteria, predictor scores, functional measurements and population frequency where available.
About this data
Variant–disease links come from ClinVar, Open Targets and UniProt, pooled from eligible public CATVariant analyses of each human protein. Evidence scores use the ACMG/AMP Bayesian points scale with computable criteria only (position among known disease variants, rarity in gnomAD, calibrated predictors, deep mutational scanning); there is no family or patient data, so they prioritise variants for expert review and never classify them.
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