Effects of TCN2 776C>G on vitamin B12, folate, and total homocysteine levels in kidney transplant patients

Effects of TCN2 776C>G on vitamin B12, folate, and total homocysteine levels in kidney transplant patients.BackgroundControversy exists regarding the possible associations between a single nucleotide polymorphism of the transcobalamin II encoding gene (TCN2 776C>G) and plasma levels of vitamin B12, folate, or total homocysteine.MethodsIn a cross-sectional study of 732 kidney allograft recipients, patients were categorized by TCN2 776C>G genotype. In univariate and multivariate linear regression models that allowed the outcome variables vitamin B12, folate, and total homocysteine plasma levels to follow a gamma distribution, we tested for possible associations of allelic variants of the TCN2 776C>G gene and these three dependent variables.ResultsThe allele frequency for TCN2 776C>G was 0.46. Heterozygosity or homozygosity for TCN2 776C>G was not associated with plasma levels of vitamin B12 (776CG, P = 0.22; 776GG, P = 0.89), folate (776CG, P = 0.91; 776GG, P = 0.84), or total homocysteine (776CG, P = 0.11; 776GG, P = 0.33) even after adjustment for several possible confounders.ConclusionWe conclude from this largest study on the subject thus far that there are no associations between allelic variants of TCN2 776C>G and plasma vitamin B12, folate, or total homocysteine plasma levels in kidney transplant patients