Methylenetetrahydrofolate Reductase Gene Polymorphisms in Patients with Down Syndrome = Methylenetetrahydrofolate Reductase Gene Polymorphisms in Patients with Down Syndrome

다국어 초록 (Multilingual Abstract)

We analyzed C677T and A1298C polymorphisms of methylenetetrahydrofolate reductase (MTHFR) by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 33 patients with Down syndrome and 100 healthy control subjects in order to understand the association between mutations of genes involved in folate metabolism and increased risk of being a child with Down syndrome. The association is still unresolved because of contradictory findings of various studies. In the patients with Down syndrome, the 677CC genotype frequency was 27.3％, 677CT 66.7％, and 677TT 6.1％. In the control group, the 677CC genotype frequency was 24.0％, 677CT 55.0％, and 677TT 21.0％. The frequency of 677TT homozygote in the patient group was 6.1％ as compared to 21.0％ in the control group. The homozygote showed an odds ratio of 0.14 (95％ CI: 0.02-0.95; P = 0.04). In the patients with Down syndrome, the 1298AA genotype was found in 50.0％, the 1298AC in 46.9％, and the 1298CC in 3.1％. In the control, the 1298AA genotype frequency was estimated at 77.0％, the 1298AC at 21.0％, and the 1298CC at 2.0％. The frequency of 1298AC heterozygote was 46.9％ in the patients whereas it was 21.0％ in the control. The heterozygote showed an odds ratio of 3.3 (95％ CI: 1.39-7.82; P= 0.007). Thus, an high prevalence of the MTHFR 677TT genotype in controls or a quite high frequency of the 1298AC genotype in the patients may provide an evidence for the presence of a differential survival advantage.