Ethnic differences in the frequency of the C677T mutation in the methylenetetrahydrofolate reductase (MTHFR) gene in healthy Israeli populations

Hyperhomocysteinemia is an Independent risk factor for arteriosclerotic vas cular disease, It can result from deficiencies of co-factors required for h omocysteine metabolism and/or from genetic disorders of its metabolism. The association between the C677T mutation in the methylenetetrahydrofolate re ductase (MTHFR) gene and vascular disease is controversial, and may be affe cted by ethnic origin. A unique feature of the Israeli population is its et hnic diversity. The aim of this study was to study the frequency of the C67 7T MTHFR mutation in healthy Israeli ethnic groups. The frequency of the mu tation was determined in 897 young healthy Jewish and Muslim Arab Israelis of eight different ethnic groups. Marked ethnic differences in the frequenc y of mutant homozygotes were found, ranging from 2% in Yemenite Jews, 4% in Sephardic Jews, 9% in Oriental Jews, 10% in Muslim Arabs, 16% in North Afr ican Jews, and 19% in Ashkenazi Jews. The frequency of mutant homozygotes w as significantly higher in Ashkenazi Jews compared to Yemenites Oriental Je ws, Sephardic Jews, and Muslim Arabs (chi (2) = 12.35 p < 0.001, <chi>(2) = 8.17 p = 0.004, chi (2) = 6.04 p = 0.01, chi (2) = 6.54 p = 0.01, respecti vely). Our findings demonstrate the need for matching ethnic background in patients and controls when studying the association between the C677T MTHFR mutation and any disease.