title: Methylenetetrahydrofolate reductase gene promoter hypermethylation in semen samples of infertile couples correlates with recurrent spontaneous abortion.
abstract: OBJECTIVE
  Is the methylation status of the methylenetetrahydrofolate reductase (MTHFR) promoter region in semen samples associated with 'recurrent spontaneous abortion' (RSA)?
  
  
  CONCLUSIONS
  MTHFR promoter hypermethylation is more frequent in semen samples from RSA couples than in semen samples from infertile couples with no history of RSA (NRSA) and affects the whole sperm population significantly more often.
  
  
  BACKGROUND
  Modifications to the MTHFR gene such as polymorphisms and promoter methylations are associated with male infertility.
  
  
  METHODS
  Retrospective cohort study of semen samples from 20 RSA couples, 147 NRSA couples and 20 fertile men between 2011 and 2012.
  
  
  METHODS
  DNA from the semen samples of RSA, NRSA and fertile men were analyzed by methylation-specific PCR amplification using primers which anneal to the methylated or unmethylated cytosine-phosphodiester bond guanine (CpG) islands within the promoter region of MTHFR. The specificity of the PCR products was assessed by DNA sequencing.
  
  
  RESULTS
  The methylated MTHFR epigenotype (including samples where it co-existed with unmethylated MTHFR epigenotypes) was detected in 75% of RSA men, 54% of NRSA men and 15% of fertile men. MTHFR methylation was observed in the whole sperm population in semen samples from 55% of RSA men compared with 8% in NRSA men (P < 0.05) and 0% in fertile men (P < 0.05). DNA sequencing analysis was fully concordant with the PCR results and revealed that when MTHFR methylation occurred, CpG islands within the promoter region were 100% methylated (hypermethylation of MTHFR promoter).
  
  
  CONCLUSIONS
  The relatively small sample size of RSA infertile couples.
  
  
  CONCLUSIONS
  The hypermethylation of the MTHFR gene promoter should be taken into consideration as a novel putative risk factor in RSA etiology.
  
  
  BACKGROUND
  Our institution has received an FAR research grant from the University of Ferrara, Ferrara, Italy. No competing interests declared.
authors.affiliation: Department of Morphology and Embryology, University of Ferrara, Ferrara 44121, Italy.
authors.forename: J C
authors.initials: JC
authors.lastname: Rotondo
authors.forename: S
authors.initials: S
authors.lastname: Bosi
authors.forename: E
authors.initials: E
authors.lastname: Bazzan
authors.forename: M
authors.initials: M
authors.lastname: Di Domenico
authors.forename: M
authors.initials: M
authors.lastname: De Mattei
authors.forename: R
authors.initials: R
authors.lastname: Selvatici
authors.forename: A
authors.initials: A
authors.lastname: Patella
authors.forename: R
authors.initials: R
authors.lastname: Marci
authors.forename: M
authors.initials: M
authors.lastname: Tognon
authors.forename: F
authors.initials: F
authors.lastname: Martini
mesh_terms: D000026:Abortion, Habitual / Q000235:genetics*; D000328:Adult; D019175:DNA Methylation; D006801:Humans; D007246:Infertility / Q000235:genetics; D007248:Infertility, Male / Q000235:genetics*; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012189:Retrospective Studies; D012661:Semen / Q000201:enzymology; D055101:Semen Analysis
chemical_list: D042965:Methylenetetrahydrofolate Reductase (NADPH2)