title: [Leber hereditary optic neuropathy: Usefulness of next generation sequencing to study mitochondrial mutations on apparent homoplasmy].
abstract: OBJECTIVE
  Leber hereditary optic neuropathy is characterized by acute and subacute visual loss, produced by mitochondrial DNA mutations.
  
  
  METHODS
  The molecular study of a family with only one affected member is presented.
  
  
  RESULTS
  In the index case and in her mother, the mitochondrial mutation m.11778G>A in the MT-ND4 was detected in the heteroplasmic state. The index case's sister, without ocular manifestations, asked for genetic counseling. The study of the mentioned mutation by Sanger sequencing identified it in an apparent homoplasmic state. However, by means of next-generation sequencing (NGS), the mutation was actually in a heteroplasmic state.
  
  
  CONCLUSIONS
  Regarding genetic counseling, verifying a mutation in homoplasmic state is really important. We have observed that NGS allows us to discriminate between high levels of heteroplasmy and homoplasmy, meaning that it is a useful technique for the analysis of apparent homoplasmic results obtained with less sensitive technique, as Sanger sequencing.
authors.affiliation: Centro de Genética Molecular Genetaq, Málaga, España. Electronic address: pcarrascos@ymail.com.
authors.forename: Pilar
authors.initials: P
authors.lastname: Carrasco Salas
authors.affiliation: Centro de Genética Molecular Genetaq, Málaga, España.
authors.forename: Carmen
authors.initials: C
authors.lastname: Palma Milla
authors.affiliation: Centro de Genética Molecular Genetaq, Málaga, España.
authors.forename: Javier
authors.initials: J
authors.lastname: López Montiel
authors.affiliation: Hospital Materno-Infantil, Hospital Universitario Carlos Haya, Málaga, España.
authors.forename: Carmen
authors.initials: C
authors.lastname: Benito
authors.affiliation: Hospital Materno-Infantil, Hospital Universitario Carlos Haya, Málaga, España.
authors.forename: Sara
authors.initials: S
authors.lastname: Franco Freire
authors.affiliation: Centro de Genética Molecular Genetaq, Málaga, España.
authors.forename: Juan
authors.initials: J
authors.lastname: López Siles
mesh_terms: D000328:Adult; D004272:DNA, Mitochondrial; D005260:Female; D005819:Genetic Markers; D005820:Genetic Testing / Q000379:methods*; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D008875:Middle Aged; D009154:Mutation; D009245:NADH Dehydrogenase / Q000235:genetics*; D029242:Optic Atrophy, Hereditary, Leber / Q000175:diagnosis / Q000235:genetics*
chemical_list: D004272:DNA, Mitochondrial; D005819:Genetic Markers; C098483:NADH dehydrogenase subunit 4; D009245:NADH Dehydrogenase
keywords: Homoplasmia; Homoplasmy; Leber hereditary optic atrophy; Mitochondrial deoxyribonucleic acid; Neuropatía óptica hereditaria de Leber; Next-generation sequencing; Secuenciación de última generación; Ácido desoxirribonucleico mitocondrial