title: Polymorphisms in MTHFR and MTRR genes associated with blood plasma homocysteine concentration and sperm counts.
abstract: OBJECTIVE
  To investigate the relationship between MTHFR and MTRR genetic variants with respect to both blood plasma homocysteine concentration and sperm counts.
  
  
  METHODS
  Polymerase chain reaction followed by specific enzymatic digestion to determine the genotype of the individuals and blood plasma homocysteine quantification by high-performance liquid chromatography.
  
  
  METHODS
  Research laboratory.
  
  
  METHODS
  Two hundred sixty-eight men seeking infertility counseling and 254 partners of infertile women.
  
  
  METHODS
  We studied three MTHFR (c.1286A → C, c.665C → T and c.203G → A) and two MTRR (c.66A → G and c.524C → T) single-nucleotide polymorphisms and characterized sperm parameters in both oligozoospermic and normospermic men. A cohort of 522 men was examined for this study. A subgroup of 103 men was constituted for quantification of Hcy levels.
  
  
  METHODS
  Semen samples were collected for determinations of sperm concentration, motility, and morphology according to World Health Organization guidelines as well as for DNA isolation. Blood samples of the corresponding individuals were obtained to quantify plasma homocysteine levels.
  
  
  RESULTS
  We did not observe a relationship between homocysteinemia and sperm counts. The MTHFR c.665C → T variant is associated with mild hyperhomocysteinemia in blood plasma in the TT homozygous state.
  
  
  CONCLUSIONS
  No association was found between MTHFR/MTRR genetic variants and sperm counts. Although no association was observed with reduced sperm counts, the MTHFR 665TT genotype is associated with a significant increase in blood plasma homocysteine levels.
authors.affiliation: Advanced Technology Laboratory, La verrière, Paris, France. debbie.montjean@pasteur.fr
authors.forename: Debbie
authors.initials: D
authors.lastname: Montjean
authors.forename: Moncef
authors.initials: M
authors.lastname: Benkhalifa
authors.forename: Lionel
authors.initials: L
authors.lastname: Dessolle
authors.forename: Paul
authors.initials: P
authors.lastname: Cohen-Bacrie
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Belloc
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Siffroi
authors.forename: Célia
authors.initials: C
authors.lastname: Ravel
authors.forename: Anu
authors.initials: A
authors.lastname: Bashamboo
authors.forename: Kenneth
authors.initials: K
authors.lastname: McElreavey
mesh_terms: D000328:Adult; D015331:Cohort Studies; D005260:Female; D005287:Ferredoxin-NADP Reductase / Q000235:genetics*; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D006710:Homocysteine / Q000032:analysis / Q000097:blood*; D006801:Humans; D007248:Infertility, Male / Q000097:blood / Q000235:genetics* / Q000503:physiopathology; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D009994:Osmolar Concentration; D020641:Polymorphism, Single Nucleotide / Q000502:physiology; D055101:Semen Analysis; D013076:Sperm Count
chemical_list: D006710:Homocysteine; C111241:methionine synthase reductase; D005287:Ferredoxin-NADP Reductase; D042965:Methylenetetrahydrofolate Reductase (NADPH2)