title: Increased frequency of combined methylenetetrahydrofolate reductase C677T and A1298C mutated alleles in spontaneously aborted embryos.
abstract: The pathogenesis of spontaneous abortion is complex, presumably involving the interaction of several genetic and environmental factors. The methylenetetrahydrofolate reductase (MTHFR) gene C677T and A1298C polymorphisms are commonly associated with defects in folate dependent homocysteine metabolism and have been implicated as risk factors for recurrent embryo loss in early pregnancy. In the present study we have determined the prevalence of combined MTHFR C677T and A1298C polymorphisms in DNA samples from spontaneously aborted embryos (foetal death between sixth and twentieth week after conception) and adult controls using solid-phase minisequencing technique. There was a significant odds ratio of 14.2 (95% CI 1.78-113) in spontaneously aborted embryos comparing the prevalence of one or more 677T and 1298C alleles vs the wild type combined genotype (677CC/1298AA), indicating that the MTHFR polymorphisms may have a major impact on foetal survival. Combined 677CT/1298CC, 677TT/1298AC or 677TT/1298CC genotypes, which contain three or four mutant alleles, were not detected in any of the groups, suggesting complete linkage disequilibrium between the two polymorphisms. The present finding of high prevalence of mutated MTHFR genotypes in spontaneously aborted embryos emphasises the potential protective role of periconceptional folic acid supplementation.
authors.affiliation: Department of Clinical Chemistry and Transfusion Medicine, Sahlgrenska University Hospital, Göteborg University, Sweden. henrik.zetterberg@clinchem.gu.se
authors.forename: Henrik
authors.initials: H
authors.lastname: Zetterberg
authors.forename: Björn
authors.initials: B
authors.lastname: Regland
authors.forename: Mona
authors.initials: M
authors.lastname: Palmér
authors.forename: Anne
authors.initials: A
authors.lastname: Ricksten
authors.forename: Lars
authors.initials: L
authors.lastname: Palmqvist
authors.forename: Lars
authors.initials: L
authors.lastname: Rymo
authors.forename: Demetrios A
authors.initials: DA
authors.lastname: Arvanitis
authors.forename: Demetrios A
authors.initials: DA
authors.lastname: Spandidos
authors.forename: Kaj
authors.initials: K
authors.lastname: Blennow
mesh_terms: D000022:Abortion, Spontaneous / Q000235:genetics*; D000483:Alleles; D019943:Amino Acid Substitution; D004622:Embryo, Mammalian / Q000502:physiology*; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D020125:Mutation, Missense; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000172:deficiency / Q000235:genetics*; D011247:Pregnancy
chemical_list: D000587:Oxidoreductases Acting on CH-NH Group Donors; D042965:Methylenetetrahydrofolate Reductase (NADPH2)