Friedreich's disease. A linkage study in southern and central Italy.

We studied linkage and linkage disequilibrium between the genetic locus of Friedreich's disease (FRDA) and two maker loci (D9S15 and D9S5) of chromosome 9q13-q21.1 in 49 subjects from 12 families in southern and central Italy. No recombination event occurred between D9S15 and D9S5, or between these polymorphisms and FRDA. Linkage disequilibrium was not observed between D9S15 or D9S5 or the extended haplotypes and FRDA, but was present between the two polymorphisms.