Regional localization by in situ hybridization of a human chromosome 9 marker tightly linked to the Friederich's ataxia locus.

In order to determine the regional localization of the Friedreich's ataxia (FA) gene on chromosome 9, the DNA probe DR47 (D9S5), which detects a restriction fragment length polymorphism (RFLP) in tight linkage with the disease, was hybridized in situ to metaphase chromosomes. Our results enable the D9S5 locus to be assigned to the 9q12-q13 region, thus indicating that this is also the localization of the FA gene.