MTHFR and MTRR polymorphisms associations with unexplained female infertility

Polymorphic alleles in genes of folate metabolism are associated with such failures of female infertility like impaired ovulation or fertilisation; however, the data about the single gene polymorphisms in genes which code the enzymes of folate metabolism are controversial. This study aimed to analyse the correlation of polymorphic variants C677T (Ala222Val), A1298C (Glu429Ala) ofMTHFRgene and A66G (Ile22Met) ofMTRRgene with the oocytes’ maturation and early embryo development in women with unexplained infertility. DNA extraction was performed with extraction kits, real-time polymerase chain reaction was applied for single nucleotide polymorphisms determinations, gonadotropinreleasing hormone antagonists were used for controlled ovarian stimulation, obtained oocytes were fertilised by the method of intracytoplasmic sperm injection, early embryo developmentin vitrowas analysed according to the Istanbul Consensus, statistical hypotheses were tested at significance levels of 0.05 and 0.01. The part of good-quality cleavage stage embryos was statistically lower for infertile patients-carriers with mutant allele A1298C ofMTHFRgene in genotype (χ2crit.=18.0361, P=0.000022). A presence of mutant allele A66G ofMTRRgene led to decrease in the number of mature MII oocytes in women with unexplained infertility (χ2crit.=11.1469, P=0.000842). No correlations of studied polymorphisms ofMTHFRandMTRRgenes with total number of received oocytes, fertilisation rate and blastocysts formation rate were found out in studied group. Examination of polymorphic variants in genes of folate metabolism C677T (Ala222Val), A1298C (Glu429Ala) ofMTHFRgene and A66G (Ile22Met) ofMTRRgene could be included to the tests necessary for women with unexplained infertility