title: Evidence against an X-linked locus close to DXS7 determining visual loss susceptibility in British and Italian families with Leber hereditary optic neuropathy.
abstract: Leber hereditary optic neuropathy (LHON) is associated with mutations of mtDNA, but two features of LHON pedigrees are not explicable solely on the basis of mitochondrial inheritance. There is a large excess of affected males, and not all males at risk develop the disease. These observations could be explained by the existence of an X-linked visual loss susceptibility gene. This hypothesis was supported by linkage studies in Finland, placing the susceptibility locus at DXS7, with a maximum lod score of 2.48 at a recombination fraction of 0. Linkage studies in 1 Italian and 12 British families with LHON, analyzed either together or separately depending on the associated mtDNA mutation, have excluded the presence of such a locus from an interval of about 30 cM around DXS7 in these kindreds, with a total lod score of -26.51 at a recombination fraction of 0.
authors.affiliation: University Department of Clinical Neurology, Institute of Neurology, Queen Square, London, England.
authors.forename: M G
authors.initials: MG
authors.lastname: Sweeney
authors.forename: M B
authors.initials: MB
authors.lastname: Davis
authors.forename: A
authors.initials: A
authors.lastname: Lashwood
authors.forename: M
authors.initials: M
authors.lastname: Brockington
authors.forename: A
authors.initials: A
authors.lastname: Toscano
authors.forename: A E
authors.initials: AE
authors.lastname: Harding
mesh_terms: D001483:Base Sequence; D002874:Chromosome Mapping; D004247:DNA / Q000097:blood; D004272:DNA, Mitochondrial / Q000097:blood / Q000235:genetics* / Q000302:isolation & purification; D004739:England; D005260:Female; D008040:Genetic Linkage; D020022:Genetic Predisposition to Disease; D006801:Humans; D007558:Italy; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation; D009838:Oligodeoxyribonucleotides; D015418:Optic Atrophies, Hereditary / Q000235:genetics* / Q000503:physiopathology; D010375:Pedigree; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D014786:Vision Disorders / Q000209:etiology / Q000235:genetics*; D014960:X Chromosome
chemical_list: D004272:DNA, Mitochondrial; D009838:Oligodeoxyribonucleotides; D004247:DNA