Biotin Deficiency, Optic Neuropathy
Conditions
Brief summary
Biotinidase is an enzyme that recycles biotin, a water-soluble vitamin essential as a coenzyme for four carboxylases that are involved in gluconeogenesis, fatty acid synthesis, and in the catabolism of several branch-chain amino acids. Biotinidase deficiency (BD) is an autosomal recessively inherited disorder. Patients with profound BD (\<10% of mean normal serum biotinidase activity) presents, usually during early childhood, with neurological (seizures, hypotonia, ataxia, developmental delay, vision problems, and/or hearing loss) and non-neurological findings (metabolic acidosis, respiratory difficulties, alopecia and/or skin rash) that may progress to coma or death if untreated. Three cases of adult-onset biotinidase deficiency with reversible optic neuropathy have recently been described in France, where there is no neonatal screening of BP. Once treated with Biotin, patients' vision was fully restored. This study aims to assess the prevalence of BP among a population of patients with idiopathic optic neuropathy, and to assess the efficacy of Biotin supplementation on visual impairment in these patients.
Interventions
None listed
Sponsors
Fondation Ophtalmologique Adolphe de Rothschild
Study design
Observational model
CASE_ONLY
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
ALL
Healthy volunteers
No
Inclusion criteria
* patient with bilateral optic neuropathy * symptoms beginning before 50 years old * diagnosed for more than 1 months * etiology unknown
Exclusion criteria
* none
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| prevalence of biotin deficiency among patients with idiopathic optic neuropathy | baseline | measure of biotinidase activity (nkat/l unit) |
Countries
France
Outcome results
None listed