title: [Clinical and genetic findings in patients with biotinidase deficiency detected through newborn screening or selective screening for hearing loss or inherited metabolic disease].
abstract: OBJECTIVE
  To evaluate clinical, biochemical and genetic findings of two series of patients with biotinidase deficiency.
  
  
  METHODS
  Fifteen cases detected through newborn screening and six through selective screening for hearing loss or metabolic disease.
  
  
  RESULTS
  No patient detected by neonatal screening had symptoms and only one case with partial biotinidase activity developed myoclonic seizures that resolved with biotin. More common mutations found among this group were p.D444H and the double mutation [p.D444H;p.A171T]. However, neurological and hearing manifestations predominated among the six symptomatic cases and mutations p.L32fs, p.G34fs, p.T401I, p.D444H, p.T532M and the novel one p.L466fs were identified. Patients with profound biotinidase deficiency and/or clinical signs were treated with pharmacological doses of biotin (10-30mg daily).
  
  
  CONCLUSIONS
  Biotinidase deficiency must be included in the newborn screening programmes in order to begin early treatment even in partial forms. Different mutations found in both series of patients suggest that routine genetic procedure of the BTD gene by direct sequencing might be useful to assign patients to the partial or profound form of the disease.
authors.affiliation: Unidad de Enfermedades Metabólicas, Hospital Clínico Universitario, Santiago de Compostela, La Coruña, Spain.
authors.forename: María Luz
authors.initials: ML
authors.lastname: Couce
authors.forename: Celia
authors.initials: C
authors.lastname: Pérez-Cerdá
authors.forename: María Teresa
authors.initials: MT
authors.lastname: García Silva
authors.forename: Angels
authors.initials: A
authors.lastname: García Cazorla
authors.forename: Elena
authors.initials: E
authors.lastname: Martín-Hernández
authors.forename: Daisy
authors.initials: D
authors.lastname: Castiñeiras
authors.forename: Merçè
authors.initials: M
authors.lastname: Pineda
authors.forename: Rosa
authors.initials: R
authors.lastname: Navarrete
authors.forename: Jaume
authors.initials: J
authors.lastname: Campistol
authors.forename: José María
authors.initials: JM
authors.lastname: Fraga
authors.forename: Belén
authors.initials: B
authors.lastname: Pérez
authors.forename: Magdalena
authors.initials: M
authors.lastname: Ugarte
mesh_terms: D000293:Adolescent; D001710:Biotin / Q000627:therapeutic use*; D043523:Biotinidase / Q000097:blood / Q000235:genetics; D028921:Biotinidase Deficiency / Q000097:blood / Q000175:diagnosis* / Q000188:drug therapy / Q000235:genetics; D002675:Child, Preschool; D034381:Hearing Loss / Q000175:diagnosis; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008659:Metabolic Diseases / Q000175:diagnosis; D009154:Mutation; D015997:Neonatal Screening; D014803:Vitamin B Complex / Q000627:therapeutic use*
chemical_list: D014803:Vitamin B Complex; D001710:Biotin; D043523:Biotinidase