Association of SCN2A single nucleotide polymorphisms with Parkinson’s disease: evidence from a case-control study

Background: A growing body of strong evidence shows that voltage-gated sodium channels genes play key roles in the development of sporadic Parkinson’s disease (sPD). However, little data have been reported on the association between single nucleotide polymorphisms (SNPs) and sPD. This study aimed to investigate the association between SCN2A gene polymorphisms and sPD. Methods: 267 patients with sPD and 267 healthy controls were included in this study. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was performed. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression of SCN2A in the serum of patients and healthy individuals. Results: The distribution of the G allele of rs2304016 or the A allele of rs17183814 in SCN2A was significantly higher in patients with sPD (p = 0.001). In subtype analysis, the frequency of the rs2304016 AG heterozygote significantly differed between the early onset PD (EOPD) and late-onset PD (LOPD) groups (p < 0.001). The frequency of the rs17183814 AG heterozygote was significantly higher in the male patients (p = 0.002). Furthermore, we found that the level of SCN2A mRNA transcription in the serum of sPD patients was significantly lower than that in the control group (p < 0.05). The serum expression level of SCN2A in patients with the AA genotype at rs17183814 was lower (p < 0.05). Conclusions: This study demonstrated a significant association between SNPs and the expression of SCN2A with sPD. These findings contribute to a better understanding of the role of SCN2A and SCN2A SNPs in sPD.