Methylation pattern of methylene tetrahydrofolate reductase and small nuclear ribonucleoprotein polypeptide N promoters in oligoasthenospermia: a case-control study

Alterations in DNA methylation patterns in several genes may lead to abnormal male sexual development and infertility. This study investigated the promoter methylation status of MTHFR and SNRPN in infertile men from Romania by quantitative methylation- specific PCR in order to investigate possible correlations with sperm abnormalities. The study groups included patients (n = 27) with a median age of 31 years (range 26-41 years) as well as controls (n = 11) with a median age of 30 years (range 24-37 years) recruited from couples seeking advice for infertility. DNA was isolated from sperm samples and promoter methylation was assessed using direct. Significant trends were detected for both genes that indicate a tendency towards promoter hypermethylation in spermatozoa with low motility (MTHFR P = 0.0032, r = 0.23; SNRPN P = 0.0003, r = 0.32) and poor morphology (MTHFR P = 0.0012, r = 0.27; SNRPN P = 0.0003, r = 0.33) but no trend was found in cases of low sperm count (MTHFR r = 0.007; SNRPN r = 0.06). The data indicate that the methylation patterns of the promoters of MTHFR and SNRPN are associated with changes in sperm motility and morphology, which could lead to male infertility. (C) 2013, Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.