Friedreich ataxia (FRDA) is a recessive neurodegenerative disorder affecting both central and peripheral nervous systems. The mutation was mapped to chromosome 9 by its tight linkage to the polymorphic loci D9S5 and D9S15. Using informative DNA markers the allele frequencies at these loci, in up to 84 unrelated healthy persons and in 16 FRDA patients of German origin, were determined. The comparison to data from other European populations did not reveal remarkable differences. No significant linkage disequilibrium could be observed between FRDA and the loci D9S5 and D9S15 in German families.