[Huntington chorea: (CAG)n repeats on gene IT 15 in Austria].

In March 1993 the gene IT 15 was identified on chromosome 4p and it was demonstrated that it contained an unstable (CAG)n trinucleotide repeat that is elongated in patients with Huntington's chorea (HC). Persons with more than 37 (CAG)n repeats tend to have a higher risk of developing the disease. Testing the (CAG)n repeats in Austrian HC patients with PCR techniques shows correspondence between the clinical diagnosis of HC and genotypes [more than 42 (CAG)n repeats]. There was a weak correlation between the number of (CAG)n repeats and age of onset, however, this finding is without diagnostic value due to the scatter of the values.