• alpha-synuclein;
  • linkage disequilibrium;
  • promoter;
  • Parkinson’s disease

Objectives –  Previous studies have found associations between Parkinson’s disease (PD) and polymorphisms located within both the alpha-synuclein gene (SNCA) promoter and other gene regions. Our aim was to study SNCA gene markers in a closely matched Norwegian PD population to examine the genetic relationship between different polymorphisms associated with the disease.

Methods –  We genotyped seven single nucleotide polymorphisms (SNPs) located in the SNCA promoter and two SNPs in the 3′ gene region and seven microsatellite markers located across the gene in a closely matched series of 236 PD patients and 236 controls. Linkage disequilibrium (LD) structure was examined, and association of single markers and gene haplotypes analyzed.

Results –  Several markers located across the SNCA gene were associated with PD, including marker alleles associated with disease in previous studies (Rep1 263-bp allele, rs356165 and rs356219).

Conclusion –  LD between associated marker alleles located across the SNCA gene suggests that a single genetic effect might explain the previous reported association in the promoter and 3′ regions.