Methylenetetrahydrofolate reductase gene polymorphisms and their association with trisomy 21.

Objectives: To verify whether the frequencies of 5,10-methylenotetrahydrofolate reductase (MTHFR) polymorphisms at positions 677 and 1298 are higher in women with children affected by trisomy 21 than in those with chromosomally normal offspring.

Methods: A case-control study was carried out with 70 women whose children had trisomy 21 and 88 controls whose children were chromosomally normal. The frequencies of polymorphisms of points C677T and A1298C of MTHFR gene coding were studied in these two groups.