A novel polymorphic triplet repeat in intron five of the alpha-synuclein gene: no evidence of expansion or allelic association with idiopathic Parkinson's disease in the Irish.

The recent discovery of two mutations associated with autosomal dominant Parkinson's disease (PD) has led to the hypothesis that the alpha-synuclein gene plays a role in the pathogenesis of PD. Here we report a novel triplet CAA repeat within the unusually large intron 5 sequence of the alpha-synuclein gene. Microsatellite analysis revealed a high degree of polymorphism within the Irish population with seven alleles detected, ranging from eight to 17 CAA repeats.