HSPA5 promoter polymorphisms and risk of Parkinson's disease in Taiwan

Endoplasmic reticulum (ER) stress induced by misfolded proteins has been implicated in Parkinson's disease (PD) pathogenesis. A malfunction of unfolded protein response (UPR) to ER stress can result in PD as well as other neurodegenerative diseases. Heat shock 70 kDa protein 5 (HSPA5) is one of the UPR chaperones reactive to ER stress to block the apoptotic process. HSPA5 promoter polymorphisms -415 G/A (rs391957), -370 C/T (rs17840761) and -180 del/G (rs3216733) and their derived haplotypes may affect promoter activity of the gene. This study examines whether these HSPA5 promoter polymorphisms are associated with the risk of Taiwanese PD and the age of disease onset using a case-control study. Polymorphisms -415 G/A and -180 del/G were completely linked in our population (D′ = 1.00, Δ² = 1.00). The genotype or allele frequency distribution of each HSPA5 polymorphism was not significantly different between the controls (n = 341) and the PD patients (n = 393). Neither the linked -415 G/A and -180 del/G nor -370 C/T polymorphism influences PD onset age. Our data suggest that the HSPA5 -415 G/A, -370 C/T, and -180 del/G polymorphisms are unlikely to play a major role in risk of developing PD in Taiwan.