Second mutation in PARK2 is absent in patients with sporadic Parkinson's disease and heterozygous exonic deletions/duplications in parkin gene

Aim of the study: Mutations in PARK2 are one of the causes of Parkinson's disease (PD). Deletions and duplications/triplications of one exon or exon groups account for a large proportion of mutations in the gene. At the present time, it is still not fully clear whether heterozygous mutations cause the development of PD. Our study aimed at conducting screening for mutations in PARK2 in patients with a sporadic form of PD to clarify the role of PARK2 in the development of PD. Materials and methods: The cohort of 327 patients with PD was screened by quantitative real-time polimerase chain reaction (PCR) with subsequent Sanger sequencing. Results: It was found that a sufficiently large proportion of these patients (21 patients, 6.4%) were carriers of heterozygous deletions or duplications in PARK2. Analysis of PARK2 exon rearrangement carriers for the presence of point mutations in PARK2 did not reveal any variants with pathogenic significance. Conclusions: Thus, our data indicate that heterozygous deletions and duplications can play an important role in the pathogenesis of PD and can be considered as dominant mutations with low penetrance.