Dataset Information

Environmental influence on the worldwide prevalence of a 776C->G variant in the transcobalamin gene (TCN2).

ABSTRACT: BACKGROUND: A 776C-->G variant (dbSNP ID: rs1801198) in the transcobalamin gene (TCN2; MIM# 275350) decreases the cellular and plasma concentration of transcobalamin and thereby influences the cellular availability of vitamin B(12). OBJECTIVE: To evaluate the worldwide prevalence of this variant and its association with homocysteine plasma level. METHODS: The study was performed in 1433 apparently healthy subjects, including Afro-Americans and Afro-Africans and in 251 Afro-Africans participants with severe malaria. RESULTS: The frequencies of the 776G allele were the highest in China (0.607; 95% CI 0.554 to 0.659), low in West Africa (Bénin and Togo, 0.178; 0.154 to 0.206), and intermediate in France (0.445; 0.408 to 0.481), Italy (0.352; 0.299 to 0.409), Morocco (0.370; 0.300 to 0.447) and Mexico (0.374; 0.392 to 0.419). The 776G genotype was more frequent in Afro-Americans from New York (16.7; 8.4 to 30.7) and in Afro-African patients with severe malaria (6.0%; 95% CI 3.7 to 9.6) than in healthy Afro-African volunteers (p = 0.0004 and p = 0.033, respectively), while no difference was observed for MTHFR 677TT and 677T alleles. A disequilibrium of TCN2 genotype distribution was recorded in patients with severe malaria, with a twofold higher GG genotype than expected (p = 0.010). An association between the TCN2 polymorphism and homocysteine was observed only in Mexico and France, the two countries with the highest rate of low plasma concentration of vitamin B(12) (<100 pmol/l). CONCLUSION: Given the dramatic heterogeneity of the 776G allele frequency worldwide, this polymorphism may be prone to a selective pressure or confers an evolutionary advantage in confronting environmental factors, one of which is malaria.

SUBMITTER: Gueant JL

PROVIDER: S-EPMC2740879 | biostudies-literature | 2007 Jun

REPOSITORIES: biostudies-literature

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Environmental influence on the worldwide prevalence of a 776C->G variant in the transcobalamin gene (TCN2).

Guéant Jean-Louis JL Chabi Nicodème W NW Guéant-Rodriguez Rosa-Maria RM Mutchinick Osvaldo M OM Debard Renée R Payet Corinne C Lu Xiaohong X Villaume Christian C Bronowicki Jean-Pierre JP Quadros Edward V EV Sanni Ambaliou A Amouzou Emile E Xia Bing B Chen Min M Anello Guido G Bosco Paolo P Romano Corrado C Arrieta Heidy R HR Sánchez Beatríz E BE Romano Antonino A Herbeth Bernard B Anwar Wafaa W Namour Fares F

Journal of medical genetics 20070112 6

<h4>Background</h4>A 776C-->G variant (dbSNP ID: rs1801198) in the transcobalamin gene (TCN2; MIM# 275350) decreases the cellular and plasma concentration of transcobalamin and thereby influences the cellular availability of vitamin B(12).<h4>Objective</h4>To evaluate the worldwide prevalence of this variant and its association with homocysteine plasma level.<h4>Methods</h4>The study was performed in 1433 apparently healthy subjects, including Afro-Americans and Afro-Africans and in 251 Afro-Afr ...[more]

PMID: 17220211

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Dataset Information

Environmental influence on the worldwide prevalence of a 776C->G variant in the transcobalamin gene (TCN2).

Publications

Environmental influence on the worldwide prevalence of a 776C->G variant in the transcobalamin gene (TCN2).

Similar Datasets

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