Disease Directory Biotinidase Deficiency
Metabolic

Biotinidase Deficiency

Also known as: BTD deficiency, late-onset multiple carboxylase deficiency, biotin recycling deficiency

Prevalence

1-5 per 10,000 (Orphanet)

Onset

Neonatal, Infantile

Type

Autosomal recessive genetic

Gene

BTD

About Biotinidase Deficiency

Biotinidase deficiency is a treatable inborn error of metabolism caused by mutations in the BTD gene, resulting in inability to recycle biotin (vitamin B7) from biotinylated enzymes. Without biotin recycling, multiple carboxylase enzymes become inactive, causing metabolic acidosis, seizures, hearing loss, and skin rash. Because it is included in newborn screening in many countries and responds completely to pharmacological biotin supplementation, most patients identified today remain asymptomatic.

Common Clinical Features

Seizures Hypotonia Skin rash and alopecia Hearing loss Optic atrophy Metabolic acidosis Developmental delay

Clinical Trial Eligibility Tips

What to know before applying to Biotinidase Deficiency trials.

Biotinidase enzyme activity level classifies patients as profound (<10%) or partial (10-30%) deficiency — trials may specify activity threshold

Biotin supplementation (5-20 mg/day) is standard and typically resolves symptoms — trials focus on optimizing dose or understanding long-term outcomes

Newborn screening detection before symptoms gives the best prognosis — screening documentation supports natural history study eligibility

Late-diagnosed patients with hearing loss or vision impairment may qualify for observational studies on irreversible complications

Patient Resources

Patient Organization

Organic Acidemia Association

Visit website ↗

Orphanet

European reference resource for rare diseases (ORPHA:79241)

View on Orphanet ↗

NORD

National Organization for Rare Disorders

Search NORD ↗

Find recruiting Biotinidase Deficiency trials

Search 500,000+ studies from ClinicalTrials.gov, filtered for Biotinidase Deficiency. Updated daily.

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