title: Genetic recombination events which position the Friedreich ataxia locus proximal to the D9S15/D9S5 linkage group on chromosome 9q.
abstract: The absence of recombination between the mutation causing Friedreich ataxia and the two loci which originally assigned the disease locus to chromosome 9 has slowed attempts to isolate and characterize the genetic defect underlying this neurodegenerative disorder. A proximity of less than 1 cM to the linkage group has been proved by the generation of high maximal lod score (Z) to each of the two tightly linked markers D9S15 (Z = 96.69; recombination fraction [theta] = .01) and D9S5 (Z = 98.22; theta = .01). We report here recombination events which indicate that the FRDA locus is located centromeric to the D9S15/D9S5 linkage group, with the most probable order being cen-FRDA-D9S5-D9S15-qter. However, orientation of the markers with respect to the centromere, critical to the positional cloning strategy, remains to be resolved definitively.
authors.affiliation: Department of Biochemistry and Molecular Genetics, St. Mary's Hospital Medical School, London, England.
authors.forename: S
authors.initials: S
authors.lastname: Chamberlain
authors.forename: M
authors.initials: M
authors.lastname: Farrall
authors.forename: J
authors.initials: J
authors.lastname: Shaw
authors.forename: D
authors.initials: D
authors.lastname: Wilkes
authors.forename: J
authors.initials: J
authors.lastname: Carvajal
authors.forename: R
authors.initials: R
authors.lastname: Hillerman
authors.forename: K
authors.initials: K
authors.lastname: Doudney
authors.forename: A E
authors.initials: AE
authors.lastname: Harding
authors.forename: R
authors.initials: R
authors.lastname: Williamson
authors.forename: G
authors.initials: G
authors.lastname: Sirugo
mesh_terms: D000293:Adolescent; D000328:Adult; D001483:Base Sequence; D002874:Chromosome Mapping; D002899:Chromosomes, Human, Pair 9; D004277:DNA, Single-Stranded; D005260:Female; D005621:Friedreich Ataxia / Q000235:genetics*; D008040:Genetic Linkage; D006801:Humans; D015810:Linkage Disequilibrium; D008297:Male; D008969:Molecular Sequence Data; D010375:Pedigree; D011995:Recombination, Genetic
chemical_list: D004277:DNA, Single-Stranded