Background: Neuroinflammation and immunopathology in Parkinson's disease (PD) are believed to be associated with genetic and environmental factors.
Objective: We conducted the current study to evaluate the Toll-like receptors (TLR4 and TLR9) genes polymorphism in patients with Parkinson's disease in northern Iran.
Methods: We extracted DNA from peripheral blood samples of 100 sporadic cases of Parkinson's disease and 100 healthy-matched controls with the mean age of 69.98 and 71.94 years, respectively. Subsequently, single-nucleotide polymorphisms (SNPs) of TLR4 and TLR9 were genotyped using restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR). Results were confirmed employing Sanger sequencing. For the analysis of our data, we used SNPStats and SPSS 22 software.
Results: Our findings indicated that the allele distribution for rs352140 of TLR9 gene was significantly different in the PD group compared with the healthy controls (p=0.02). Moreover, rs352140 T allele was observed to be correlated with PD reduced risk (TT + TC vs. CC). The dominant rs352140 model was approved as the most acceptable inheritance model for fitting the data (OR 0.41, 95% CI 0.23-0.75, p=0.0031). Additionally, haplotype analysis revealed a significant correlation between TLR9 polymorphisms and Parkinson's disease.
Conclusion: The results of this study indicated that rs352140T of TLR9 gene was a protective factor in Parkinson's disease. Furthermore, this SNP could be regarded as a prognostic factor. However, this conclusion should be confirmed by further investigations.