Investigation of the polymorphisms of deleted in azoospermia like (DAZL), 5-metylentetrahydrofolate reductase (MTHFR) and follicle stimulating hormone receptor (FSHR) genes in male infertility

Male infertility is a genetically heterogeneous health condition and is difficult to identify due to the complexity of interactions between individuals and environmental factors. Genetic studies on male infertility are intrinsically difficult and complex since more than 50% of infertility cases are of male origin. Low sperm count, no sperm, poor sperm quality or all of them in addition to anatomical problems, hormonal imbalances and genetic defects of the affected individuals are among the causes of more than 90% of male infertility cases. In addition to genetic causes, factors such as the general health status of a man, lifestyle selection, social status and work environment also have a widespread effect on fertility. Researchers have detected genetic polymorphisms in MTHFR, DAZL and FSHR genes or several single nucleotide polymorphisms (SNPs) in patient groups, however, very few of them were related to male infertility. Limited number of studies have been published about male infertility at the molecular genetic level, in Turkey. In this study, we investigated the polymorphisms including 677C/T (rs1801133) and 1298A/C (rs1801131) for MTHFR gene, 260A/G and 386A/G (rs121918346) for DAZL gene, -29G/A (rs1394205), 919A/G (rs6165) and 2039A/G (rs6166) for FSHR gene using PCR-RFLP technique in patients diagnosed with infertility and azoospermia. We aimed to determine the relationship between spermatogenesis and allele frequencies. In this thesis, we selected an infertile patient population diagnosed with normal karyotype, no deletion detected as a result of Y-deletion screening and no evidence of hormonal imbalances related to infertility and who has registered in between the years 2014 and 2016. Patients were grouped as azoospermia or oligospermia according to their spermiogram results. We investigated the association of FSHR, MTHFR and DAZL gene polymorphisms with male infertility in 156 azoospermic and oligospermic individuals. In this study, we did not detect any polymorphism that was statistically related to male infertility. We conclude that the FSHR, MTHFR and DAZL gene polymorphisms are not among the genetic factors that may cause male infertility. Anahtar kelimeler: RFLP, Erkek infertilitesi, DAZL, MTHFR, FSHR, Azoospermi