Association of TLR4 gene polymorphisms with sporadic Parkinson's disease in a Han Chinese population

Parkinson's disease (PD) is considered as a multifactorial disorder involving complex interactions between genetic and environmental factors, while previous studies point to a pivotal role of neuroinflammation in the pathophysiology of PD. As a member of pattern recognition receptors, TLR4 plays an important role in the immune response and inflammatory responses. Growing evidences suggest that mutation of TLR4 gene may be connected with the development of PD. The objective of this study was to evaluate whether genetic polymorphisms of the TLR4 gene are associated with PD susceptibility. We genotyped three single-nucleotide polymorphisms of the TLR4 gene (rs1927911, rs1927914 and rs10116253) by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) in unrelated 380 PD patients and 380 healthy-matched controls. Our study revealed that rs1927914 C allele carriers and C allele were probably related to a decreased risk of PD (p = 0.032 and p = 0.028, respectively) as well as male PD (p = 0.034) and early-onset PD (EOPD) (p = 0.023). In addition, there were significant differences in genotype and allele distribution in male PD patients and its healthy-matched control subgroup (p = 0.035 and p = 0.012, respectively). For rs1927911 and rs10116253 polymorphisms, genotype or allele frequencies did not differ between groups. Our data suggest that the TLR4 gene might contribute to the risk of developing PD in Han Chinese and rs1927914 polymorphism may be a protective factor for sporadic PD, male PD and EOPD.