title: Late presentation of biotinidase deficiency with acute visual loss and gait disturbance.
abstract: An unusual presentation of biotinidase deficiency is described. The disorder classically presents in infancy or early childhood with intractable seizures, hypotonia, ataxia, hearing loss, dermatitis, and alopecia. A 5-year-old girl developed acute visual loss associated with optic atrophy, and disturbance of gait with predominantly lower-limb pyramidal signs. She had no seizures, and skin, hair, hearing, and intellect were normal. Biotinidase deficiency was confirmed biochemically and she responded well to biotin therapy. A diagnosis of biotinidase deficiency should be considered in children with unexplained bilateral optic neuropathy, particularly when there is accompanying gait disorder.
authors.affiliation: Institute of Child Health, London, UK.
authors.forename: S
authors.initials: S
authors.lastname: Rahman
authors.forename: S
authors.initials: S
authors.lastname: Standing
authors.forename: R N
authors.initials: RN
authors.lastname: Dalton
authors.forename: M G
authors.initials: MG
authors.lastname: Pike
mesh_terms: D000581:Amidohydrolases / Q000172:deficiency*; D001710:Biotin / Q000627:therapeutic use; D043523:Biotinidase; D002675:Child, Preschool; D005260:Female; D005684:Gait; D006801:Humans; D008661:Metabolism, Inborn Errors / Q000175:diagnosis; D009896:Optic Atrophy / Q000150:complications; D016896:Treatment Outcome; D014786:Vision Disorders / Q000209:etiology*
chemical_list: D001710:Biotin; D000581:Amidohydrolases; D043523:Biotinidase