Parkin (PARK 2) Mutations Are Rare in Czech Patients with Early-Onset Parkinson's Disease

Objective: The aim of the study is to determine the frequency of parkin allelic variants in Czech early-onset Parkinson's disease patients and healthy controls. Methods: A total of 70 early-onset Parkinson's disease patients (age at onset <= 40 years) and 75 controls were screened for the sequence variants and exon rearrangements in the parkin gene. Results: Parkin mutations were identified in five patients (7.1%): the p. R334C point mutation was present in one patient, four patients had exon deletions. The detected mutations were observed in the heterozygous state except one homozygous deletion of the exon 4. No mutations were obtained in control subjects. A novel sequence variant p.V380I (c.1138G>A) was identified in one control. Non-pathogenic polymorphisms p. S167N and p.D394N were seen in similar percentage in patients and controls, polymorphism p.V380L was almost twice as frequent in controls as in patients. Conclusions: Our study contributes to the growing body of evidence on the low frequency of the parkin mutations in the early-onset Parkinson's disease suggesting the potential role of other genes in the pathogenesis of the disease.