The percentage of hemimethylation (both methylated and unmethylated alleles) of MTHFR was 29% among idiopathic infertile patients and 13% among fertile controls, while the prevalence of full methylation (only the methylated allele) of MTHFR in idiopathic infertile males and controls were 16% and 2%, respectively. This evidence concerns the gene MTHFR and Infertility.