RESUMO
<p><b>Objective</b>To study the relationship of the single nucleotide polymorphisms (SNP) rs34349826 (c.104 A>G) and rs6521 (c.114 C>G) of the luteinizing hormone beta-subunit (LHB) gene with male infertility in Chinese men.</p><p><b>METHODS</b>This case-control study included 405 males with primary infertility (the infertility group) and 424 normal fertile men (the control group), the former again divided into subgroups of oligospermia, severe oligozoospermia and azoospermia according to the sperm concentration. Clinical data were collected from all the subjects and genomic DNA obtained from their peripheral blood for genotyping rs34349826 and rs6521 of the LHB gene by Sequence MassArray. We analyzed the correlation of male infertility with the SNPs of the two loci using the logistic regression model as well as its association with their haplotype combination with the SHEsis online software.</p><p><b>RESULTS</b>There were statistically significant differences between the control and infertility groups in the semen volume (［3.51 ± 1.36］ vs ［3.74 ± 1.71］ ml, P <0.05), sperm concentration (［79.21 ± 61.60］ vs ［27.37 ± 30.80］ ×10⁶/ml, P <0.01), percentage of progressively motile sperm (［39.40 ± 9.64］ % vs ［11.90 ± 14.72］ %, P <0.01), and levels of serum luteinizing hormone (LH) (［3.29 ± 1.39］ vs ［6.25 ± 4.83］ IU/L, P <0.01) and follicle-stimulating hormone (FSH) (［4.56 ± 2.31］ vs ［15.64 ± 17.03］ IU/L, P <0.01). Logistic regression analysis revealed no correlation between male infertility and the genotypes of the rs34349826 and rs6521 loci of the LHB gene, and similar results were found in the subgroups of the infertile males. SHEsis analysis on the haplotypes of the rs34349826 and rs6521 loci showed the GG genotype combination to be a protective factor against male infertility.</p><p><b>CONCLUSIONS</b>The rs34349826 and rs6521 loci of the LHB gene were not related to male infertility, which can be further confirmed by larger-sample studies. The GG genotype combination is a protective factor against male infertility.</p>