Follicle-stimulating hormone receptor gene haplotypes and male infertility in estonian population and meta-analysis.

Follicle-stimulating hormone (FSH) is crucial for male fertility and it exerts its effects via a gonad-specific receptor (FSHR). In the present study, the common G-29A, A919G, and A2039G polymorphisms in the FSHR gene were analysed in 150 (36 non-obstructive azoospermia and 114 individuals with oligozoospermia) patients and 208 normozoospermic men. The results showed that the FSHR polymorphisms were not associated with either azoo- or oligozoospermia as the distributions of alleles, genotypes, and haplotypes among patients and controls were similar. Amongst normozoospermic men, those carrying at least one minor A allele (GA and AA genotypes) of the G-29A polymorphism had a smaller mean testicular volume compared to men with GG homozygosity (25.8 ml vs. 27.4 ml, respectively; P=0.013). In a subsequent meta-analysis combining our data with previous studies, the G-29-A919-A2039 haplotype was shown to be more prevalent in normozoospermic men than in azoospermic patients (38.4% vs. 33.9%, respectively; chi(2)test, P=0.045), indicating that this haplotype may be a protective factor against male sterility. In conclusion, we suggest that FSHR haplotypes are not considerable risk factors for spermatogenic failure. The protective nature of G-29-A919-A2039 haplotype cannot be concluded without additional studies.