[DNA-diagnosis of bulbospinal muscular atrophy (Kennedy's disease)].

Bulbospinal muscular atrophy--a rare disease with X-linked recessive type of inheritance. It is caused by expansion of trinucleotide repetitions in the gene of androgenic receptor (AR). We elaborated a method of DNA-testing with usage of nonradioactive registration of mutant alleles of AR gene. DNA-diagnosis was performed in 16 patients with clinical pattern of bulbospinal muscular atrophy and diagnosis was confirmed in 11 patients. Carriage of mutant alleles was found in 7 women--relatives of the patients. Presymptomatic diagnosis revealed the presence of mutant alleles in 2 boys. Unstability of alleles of mutant AR gene was observed in one family: in sons there was more (upon 5) of CAG-triplets.