Association of PFKM gene polymorphisms and susceptibility to cryptorchidism in a Chinese Han population

Cryptorchidism is one of the most common congenital anomalies in newborn boys. There are various risk factors that have been verified to have relationship with cryptorchidism, including exogenous and genetic, but the pathogenesis of cryptorchidism remains unclear. PFKM gene is a critical gene encodes for a regulatory enzyme, which limits the rate in the pathway of glycolysis. We assumed that cryptorchidism risk may associated with PFKM gene single-nucleotide polymorphisms (SNPs). Thus we selected three tag SNPs in the PFKM gene and aimed to investigate the possible association between PFKM gene polymorphisms and cryptorchidism risk.

The SNPs were genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. 140 cases and 227 controls were enrolled in this study, including 105 unilateral cryptorchidism and 35 bilateral cases. The testis position was decided by the higher one in bilateral cases.

The frequency of allele G of SNP rs2228500 is increased in cryptorchidism patients compared to that in controls (p < 0.05). Genotypic frequencies of rs2228500 are associated with the susceptibility of cryptorchidism in the codominant model (p < 0.05). And compared with G/G genotype in the dominant model, notable decreased frequencies of A carriers (A/G-A/A genotypes) were observed in cryptorchidism patients (p = 0.0069, OR = 1.80, 95% CI  1.17-2.75).

This research first revealed that PFKM gene polymorphisms were associated with cryptorchidism in a Chinese Han population. We have offered primary evidence that the G allele and the G/G genotype of rs2228500 SNP in the PFKM gene are more frequent in patients with cryptorchidism than healthy controls.