MTHFRC 677T Gene Polymorphism and Homocysteine in North China Patients with Varicocele

To investigate the correlation between methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphism, homocysteine, and male infertility with varicocele in North China. One Hundred infertile males with varicocele (VC; grade II-III, VC group) and 100 healthy males with normal semen parameters and no varicocele (NC group) were recruited for PCR microarray, blood and semen testing. Compared with the CC genotype in the NC group, the TT genotype in the NC group and the CC genotype in the VC group showed no significant changes in sperm motility (P = 0.191; P = 0.130), sperm density (P = 0.591, P = 0.643), plasma homocysteine level (P = 0.511; P = 0.677), and seminal plasma MDA (P = 0.752; P = 0.451). In contrast, VC patients with the TT genotype had higher plasma homocysteine level and seminal plasma MDA levels (P  < 0.001), lower partial pressure of oxygen in seminal pulse (PO₂; P  < 0.001) and poorer sperm quality (P  < 0.001), as compared with the CC genotype. This suggests that MTHFR C677C>T may not be a risk factor for male Varicocele in North China. However, this may affect the oxidative stress associated with homocysteine expression, which in turn affects semen parameters in VC patients. Larger studies are needed to validate our findings.