PINK1 mutation heterozygosity and the risk of Parkinson's disease

Mutations in the PTEN-induced kinase 1 (PINK1) gene have been identified in recessively inherited and sporadic early-onset parkinsonism (EOP).

A total of 131 Norwegian patients diagnosed with Parkinson's disease were included. Of them, 89 participants had EOP (onset < or = 50 years); the remaining had familial late-onset disease (mean age at onset 64 years). PINK1 analysis included sequencing and gene dose assessment. Mutations were examined in 350 controls.

Heterozygous missense mutations in PINK1 were found in 3 of 131 patients; none of the patients carried homozygous or compound heterozygous mutations. One of these three patients had a father affected by Parkinson's disease, and he carried the mutation. Three new and seven known polymorphic variants were identified, although none seemed to be associated with disease risk.

PINK1 mutations are rare in Norwegian patients with EOP and familial Parkinson's disease. However, the data suggest that some heterozygous mutations might increase the risk of developing Parkinson's disease.