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 [θ] = .01) and D9S5 (Z = 98.22; θ = .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.
|Number of pages||11|
|Journal||American Journal of Human Genetics|
|Publication status||Published - Jan 1993|
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