Lack of evidence for association of a parkin promoter polymorphism with early-onset Parkinson's disease in a Chinese population

Mutations in parkin are a common cause of early-onset autosomal recessive Parkinson's disease (PD). A single nucleotide polymorphism in the parkin promoter (rs9347683, −258T/G) has been reported to be associated with PD and shown to functionally affect gene transcription in luciferase reporter assays. In addition, homozygosity for the minor allele of rs9347683 may significantly reduce the age of onset of PD. We investigated the polymorphism in a cohort of cases with early-onset PD previously excluded for mutations in PD associated loci. We did not observe any differences in allele or genotype frequencies between the cases and the controls and there was no evidence for an effect on age of disease onset. Our results do not support a role for this variant in early-onset PD.