Mayor-Olea, AlvaroCallejón, GonzaloPalomares, Arturo RJiménez, Ana JGaitán, María JesúsRodríguez, AlfonsoRuiz, MaximilianoReyes-Engel, Armando2013-10-032013-10-032008-11-28Mayor-Olea A, Callejón G, Palomares AR, Jiménez AJ, Gaitán MJ, Rodríguez A, et al. Human genetic selection on the MTHFR 677C>T polymorphism. BMC Med. Genet. 2008; 9:104http://hdl.handle.net/10668/1309Journal Article; Research Support, Non-U.S. Gov't;BACKGROUND The prevalence of genotypes of the 677C>T polymorphism for the MTHFR gene varies among humans. In previous studies, we found changes in the genotypic frequencies of this polymorphism in populations of different ages, suggesting that this could be caused by an increase in the intake of folate and multivitamins by women during the periconceptional period. The aim was to analyze changes in the allelic frequencies of this polymorphism in a Spanish population, including samples from spontaneous abortions (SA). METHODS A total of 1305 subjects born in the 20th century were genotyped for the 677C>T polymorphism using allele specific real-time PCR with Taqman probes. A section of our population (n = 276) born in 1980-1989 was compared with fetal samples (n = 344) from SA of unknown etiology from the same period. RESULTS An increase in the frequency of the T allele (0.38 vs 0.47; p < 0.001) and of the TT genotype (0.14 vs 0.24; p < 0.001) in subjects born in the last quarter of the century was observed. In the 1980-1989 period, the results show that the frequency of the wild type genotype (CC) is about tenfold lower in the SA samples than in the controls (0.03 vs 0.33; p < 0.001) and that the frequency of the TT genotype increases in the controls (0.19 to 0.27) and in the SA samples (0.20 to 0.33 (p < 0.01)); r = 0.98. CONCLUSION Selection in favor of the T allele has been detected. This selection could be due to the increased fetal viability in early stages of embryonic development, as is deduced by the increase of mutants in both living and SA populations.enFeto abortadoFrecuencia de los GenesGenotipoMetilenotetrahidrofolato reductasa (NADPH2)Reacción en cadena de la polimerasaPolimorfismo genéticoSelección genéticaEspañaMedical Subject Headings::Named Groups::Persons::Age Groups::AdultMedical Subject Headings::Health Care::Health Care Quality, Access, and Evaluation::Quality of Health Care::Epidemiologic Factors::Age FactorsMedical Subject Headings::Check Tags::FemaleMedical Subject Headings::Phenomena and Processes::Genetic Phenomena::Gene FrequencyMedical Subject Headings::Phenomena and Processes::Genetic Phenomena::GenotypeMedical Subject Headings::Organisms::Eukaryota::Animals::Chordata::Vertebrates::Mammals::Primates::Haplorhini::Catarrhini::Hominidae::HumansMedical Subject Headings::Check Tags::MaleMedical Subject Headings::Chemicals and Drugs::Amino Acids, Peptides, and Proteins::Proteins::Flavoproteins::Methylenetetrahydrofolate Reductase (NADPH2)Medical Subject Headings::Analytical, Diagnostic and Therapeutic Techniques and Equipment::Investigative Techniques::Genetic Techniques::Nucleic Acid Amplification Techniques::Polymerase Chain ReactionMedical Subject Headings::Phenomena and Processes::Genetic Phenomena::Genetic Variation::Polymorphism, GeneticMedical Subject Headings::Phenomena and Processes::Genetic Phenomena::Genetic Processes::Selection, GeneticMedical Subject Headings::Geographicals::Geographic Locations::Europe::SpainMedical Subject Headings::Named Groups::Persons::Age Groups::Adult::Young AdultMedical Subject Headings::Anatomy::Embryonic Structures::Fetus::Aborted Fetusresearch article19040733open access10.1186/1471-2350-9-1041471-2350PMC2610030