Low frequency of the PARK2 gene mutations in Polish patients with the early-onset form of Parkinson disease

Abstract

Objective Mutations in the PARK2 ( Parkin) gene result in an early-onset autosomal recessive form of Parkinson Disease (EO-PD). Although the frequency of the PARK2 mutations in EO-PD patients according to several studies is high and has been reported in up to 50% in familial and 19% in sporadic cases, these data remain controversial. Methods We performed PARK2 gene analysis for a group of 79 Polish EO-PD patients with onset of disease below the age of 40. All exons were directly sequenced and the exons' copy number variations were analyzed. Results Mutations in PARK2 gene were found in 3 patients (3.8%), in two sporadic cases in both alleles (2.5%) and in a familial case in only one allele (1.3%). We identified point mutations as well as exon rearrangements (duplication, deletion). Conclusions The frequency of the PARK2 mutations our Polish group with EO-PD seems to be lower than in other previously described groups.