Lack of association of mortalin (HSPA9) and other mitochondria-related genes with risk of Parkinson's and Alzheimer's diseases.

We investigated the role of mortalin (HSPA9) and its interaction with other mitochondria-related genes (parkin, PINK1, DJ1, and COQ2) as a risk factor for Parkinson's disease (PD) and Alzheimer's disease (AD) in 500 PD, 400 AD, and 500 control subjects. The HSPA9 variants identified by direct sequencing or its interaction with other genes assessed by genetic risk scores did not show a significant association with PD or AD risk. Our findings did not provide a strong evidence for the role of HAPA9 and its interaction with other mitochondria-related genes as a genetic risk factor for PD or AD.