IEMbase 0093: BTD-related biotinidase deficiency
Scope
| Field | Value |
|---|---|
| IEMbase ID | 93 |
| Nosology | 21.7.01.01 |
| Gene | BTD |
| External IDs | OMIM:253260 |
| Generated mapping | MAPPED to Biotinidase_Deficiency.yaml |
| Candidate DisMech targets | Biotinidase_Deficiency.yaml |
| Review date | 2026-07-07 |
IEMbase phenotype signal
IEMbase represents this as autosomal recessive BTD-related biotinidase deficiency, with alternate labels late-onset multiple carboxylase deficiency and BTD deficiency. Treatability is marked yes, and prevalence is listed near 1:61,000.
The characteristic biochemical rows are 3-methylcrotonylglycine, C5-OH acylcarnitine in dried blood spot or plasma, plasma biotinidase, urinary 3-hydroxyisovaleric acid, and urinary 3-hydroxypropionic acid. The wider panel also includes urinary methylcitric acid and plasma lactate.
The characteristic clinical rows are glossitis, stomatitis, and mitral valvulitis.
Treatment is biotin.
DisMech phenotype coverage
The generated mapping is correct. Biotinidase_Deficiency.yaml directly models
BTD deficiency as impaired biotin recycling causing secondary multiple
carboxylase deficiency.
DisMech covers the core biochemical pattern: reduced biotinidase enzyme activity, C5-OH acylcarnitine, 3-hydroxyisovaleric acid, C3-related propionylcarnitine context, organic aciduria, lactate, and metabolic acidosis. It also covers the major clinical consequences of untreated or late-treated disease, including seizures, developmental delay, hypotonia, rash, alopecia, hearing loss, optic neuropathy, respiratory features, and lifelong biotin treatment with newborn-screening context.
Concordance and completeness
Judgement: high concordance.
IEMbase adds several compact clinical rows that are not prominent in the local entry: glossitis, stomatitis, and mitral valvulitis. DisMech is substantially richer for mechanism, severity classes, genotype-phenotype notes, treatment rationale, newborn screening, and long-term neurologic/auditory/visual risks.
Curation actions
- Keep the generated mapping to
Biotinidase_Deficiency.yaml. - Consider adding glossitis, stomatitis, and mitral valvulitis as review targets if supported by source evidence.
- Keep IEMbase biochemical compartments in mind if future structured lab curation distinguishes dried blood spot, plasma, and urine assays.