Genetic Polymorphisms in the Homocysteine Metabolism Pathway and Thrombosis in Thai Children: A Case Control Study.

Hyperhomocysteinemia is a known risk factor for thrombosis in both adults and children. Mutations of genes encoding the enzymes in homocysteine metabolism are predicted to cause elevation of homocysteine and increase the risk of thrombosis. Therefore, this study objectives are to determine the prevalence of methylenetetrahydrofolate reductase (MTHFR) 677C->T, 1298A->C; methionine synthase (MS) 2756A->G, and cystathione β-synthase (CBS) 884ins68 in Thai ethnic patients, aged ≤18 years, and their relationship to thrombosis. The population consisted of 91 patients, from 2 medical institutes in Thailand, first diagnosed with thrombosis. The control group was 169 healthy, Thai children matched for age (mean ± SD in cases/controls = 9.4 ± 5.7 / 9.3 ± 5.7 years, p = 0.9) and sex (male/female in cases/controls = 57.1%/42.9%/53.8%/46.2%, p = 0.7). Genotyping was performed using standard PCR/restriction enzyme assays. The prevalence and allele frequency of the genes are shown in Table 1. The polymorphisms of individual genes and the combinations between the genotype did not affect plasma homocysteine level. The details are shown in Table 2. Conclusion, the prevalence of MTHFR 677C->T, 1298A->C, MS 2756A->G, and CBS 884ins68 in Thai population was lower than Caucasian population; and did not cause the increase risk for thrombosis in Thai children.