Association of C677T and A1298C polymorphisms of the MTHFR gene with maternal risk for Down syndrome: A meta-analysis of case-control studies.

Background: Several studies around the world support the hypothesis that genetic polymorphisms involved in folate metabolism could be related to the maternal risk for Down syndrome (DS). Most of them investigated the role of MTHFR C677T and/or A1298C polymorphisms as maternal risk factors for DS, but their results are often conflicting and still inconclusive.

Methods: We conducted a systematic review and meta-analysis to clarify the association of MTHFR C677T and/or A1298C polymorphisms with the maternal risk of DS.

Association between MTHFR C677T and A1298C gene polymorphisms and maternal risk for Down syndrome: A protocol for systematic review and/or meta-analysis.

Background: Down syndrome (DS) is one of the most common chromosomal abnormalities among live-born babies and one of the best-known intellectual disability disorders in humans. Errors leading to trisomy 21 are primarily arising from defects in chromosomal segregation during maternal meiosis (about 88% of cases), and the focus of many investigations has been to identify maternal risk factors favoring chromosome 21 malsegregation during oogenesis. Maternal polymorphisms of genes required for folate metabolism are the most investigated risk factors for the birth of children with DS.