Genetic Polymorphisms in DRD4 and Risk for Parkinson's Disease Among Eastern Indians

Background: Genetic factors, including causal gene and modifier genes, contribute significantly in PD pathogenesis in an ethnicity-dependent manner. Dopamine Receptor 4 (DRD4), involved in dopamine metabolism is one such modifier locus for PD. Objective: To identify the potential association of DRD4 polymorphic variants with PD among Eastern Indians. Methods and Materials: PD-related DRD4 variants were genotyped among 291 PD patients and 265 ethnically matched controls from Eastern India. Results and Conclusion: Among the three DRD4 variants, only the 120 bp duplicated allele [P = 0.036; Odds ratio: 1.323; 95% CI: 1.014-1.725] and its homozygous genotype [P= 0.034; Odds ratio: 1.452; 95% CI: 1.025-2.057] were found as risk factors for overall PD and sporadic PD among Eastern Indians. However, no other disease-associated variant or haplotype was identified. Therefore, in conclusion, our study demonstrates that DRD4 plays a small role in PD pathogenesis among Eastern Indians.