Polimorfismos no gene MTHFR – Metilenotetrahidrofolato redutase (C677T e A1298C) envolvidos no metabolismo do folato, em mães de pacientes com Síndrome de Down

Abstract

Down Syndrome, or Trissomy 21, is the most recurrent chromosomal disturb among newborns. This trissomy is, in most of the cases (95% of them) launched by maternal meiotic non-disjunction during meiosis I. With the exception of advanced maternal age, other risk factors for this non-disjunction are not well established. Recent preliminary studies suggest that the abnormal metabolism of folate and polymorphisms at the MTHFR gene (C677T and A1298C) might be maternal risk factors for Down Syndrome. With the purpose of verifying the frequency of the polymorphisms in the MTHFR gene (C677T and A1298C) and a possible association of them, as maternal risk factors for Down Syndrome, we performed a case-control study in 41 mothers of Down Syndrome children (who attend APAE) and 39 controls from the city of Belém-PA. Our results demonstrate that the distribution of the genotypes for both of the polymorphisms amidst the mothers studied and controls were in Hardy-Weinberg equilibrium. We did not find differences among the ratio of the studied mothers e control mothers. These results suggest that these isolated and/or haplotype-shaped mutations can not be considered as a maternal risk for Down Syndrome for the analyzed population, but as common polymorphisms among this same population.