Follicle-Stimulating Hormone Receptor Gene Haplotypes and Male Infertility in Estonian Population and Meta-Analysis

Abstract

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; χ²test, 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.

KEYWORDS:

• follicle-stimulating hormone receptor gene
• male infertility
• single nucleotide polymorphisms

ACKNOWLEDGMENTS

The authors acknowledge all voluntary participants of the study. The study was supported by the Estonian Science Foundation (grants nos. 6498 and 6585), the Estonian Ministry of Education and Science (core grants nos. SF0180044s09 and PBGMR07903), and the European Union through the European Regional Development Fund through the Centre of Excellence in Genomics, Estonian Biocentre and University of Tartu.

Declaration of Interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.