Association of rs3783641 single‐nucleotide polymorphism in GTP cyclohydrolase 1 gene with post‐herpetic neuralgia

Post‐herpetic neuralgia ( PHN ) is a well‐established clinical problem with potential severe personal and socioeconomic implications. GTP cyclohydrolase 1 ( GCH 1 ) gene, which encodes the rate‐limiting enzyme in tetrahydrobiopterin synthesis, has been strongly implicated to be associated with neuropathic pain in previous animal and human studies. The rs3783641 (T > A) single‐nucleotide polymorphism ( SNP ) in the GCH 1 gene is functional. Here we examine the association between rs3783641 and PHN . A total of 292 subjects including 103 PHN patients, 87 herpes zoster ( HZ ) patients and 102 healthy controls were enrolled in this study. The rs3783641 polymorphisms were detected via the high‐resolution melting curve ( HRM ) method. There were statistical differences between PHN group and the other two groups in genotype distribution ( P  = 0.029 and 0.017, respectively) and allele frequency ( P  = 0.032 and 0.005, respectively) of rs3783641. The proportion of subjects with AA genotype in the PHN group was significantly lower compared to HZ group and control group ( P  = 0.026 and 0.016, respectively). The frequency of A allele was lower in the PHN group than in control group ( P  = 0.005), and the frequency of T allele in the PHN group was higher than in HZ group and control group ( P  = 0.001 and 0.003, respectively). The results of this study suggest that the rs3783641 SNP in the GCH 1 gene is associated with PHN , and the AA genotype showed a protective effect in PHN .