Rare and novel variants of PRKN and PINK1 genes in Vietnamese patients with early-onset Parkinson's disease.

Background: Early-onset Parkinson's disease (EOPD) refers to that of patients who have been diagnosed or had onset of motor symptoms before age 50, accounting for 4% of Parkinson's disease patients. The PRKN and PINK1 genes, both involved in a metabolic pathway, are associated with EOPD.

Methods: To identify variants associated with EOPD, coding region of PARKIN and PINK1 genes in 112 patients and 112 healthy individuals were sequenced. Multiplex ligation-dependent probe amplification kit was used to determine EOPD patients that carried mutations in PRKN and PINK1 genes.

Results And Conclusion: Three rare and three novel mutations in total of 14 variants of PARKIN and PINK1 were detected in the EOPD cohorts. Mutations of PRKN and PINK1 genes were found in five (4.4%) patients, which were four patients with compound heterozygous variants in the PRKN and one case with a homozygous mutation of the PINK1 gene. The novel mutations might reduce the stability of the PRKN and PINK1 protein molecules. The frequency of homozygous mutant genotype p.A340T of the PINK1 in the EOPD cohort was higher than in control (p = 0.0001, OR = 5.704), suggesting this variant might be a risk factor for EOPD. To the best of our knowledge, this is the first study of PRKN and PINK1 genes conducted on Vietnamese EOPD patients. These results might contribute to the genetic screening of EOPD in Vietnam.