title: Leber's hereditary optic neuropathy: clinical and molecular profile of a Brazilian sample.
abstract: OBJECTIVE
  The aim of this study was to describe clinical features and search for primary mitochondrial DNA (mtDNA) mutations in 13 unrelated Brazilian patients with Leber's hereditary optic neuropathy (LHON).
  
  
  METHODS
  Analysis of the G11778A, G3460A, and T14484C mutations was done by polymerase chain reaction and restriction fragment length polymorphism, and mutations were confirmed by direct sequencing. Mean age of onset was 24.5 years and all cases were bilateral.
  
  
  RESULTS
  Sex ratio (12M:1F) and frequency of simultaneous involvement (9/13) were higher than in other studies. In nine cases there was familial recurrence: 24 male and two female relatives. Ten patients had a mutation: G11778A in six, T14484C in three and one G3460A. The frequency of patients bearing a primary mutation was lower than that described in multicentric studies but similar to that observed among Asians. A higher frequency of the T14484C mutation was detected.
  
  
  CONCLUSIONS
  The contribution of Amerindians and Africans to the Brazilian mtDNA pool may account for differences in the type and frequency of primary LHON mutations.
authors.affiliation: Departamento de Genética Médica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, São Paulo, Brasil. atmg@fcm.unicamp.br
authors.forename: Andréa Trevas
authors.initials: AT
authors.lastname: Maciel-Guerra
authors.forename: Luciene Maria
authors.initials: LM
authors.lastname: Zanchetta
authors.forename: Marcela Scabello
authors.initials: MS
authors.lastname: Amaral Fernandes
authors.forename: Paula Baloni
authors.initials: PB
authors.lastname: Andrade
authors.forename: Paulo Maurício
authors.initials: PM
authors.lastname: do Amor Divino Miranda
authors.forename: Edi Lúcia
authors.initials: EL
authors.lastname: Sartorato
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D001938:Brazil / Q000453:epidemiology; D004272:DNA, Mitochondrial / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D029242:Optic Atrophy, Hereditary, Leber / Q000453:epidemiology / Q000235:genetics*; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D012744:Sex Ratio; D055815:Young Adult
chemical_list: D004272:DNA, Mitochondrial