Effects of TCN2 776C>G on vitamin B, folate, and total homocysteine levels in kidney transplant patients.
BACKGROUND
Controversy exists regarding the possible associations between a single nucleotide polymorphism of the transcobalamin II encoding gene (TCN2 776C>G) and plasma levels of vitamin B(12), folate, or total homocysteine.


METHODS
In 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 B(12), 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.


RESULTS
The allele frequency for TCN2 776C>G was 0.46. Heterozygosity or homozygosity for TCN2 776C>G was not associated with plasma levels of vitamin B(12) (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.


CONCLUSIONS
We 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 B(12), folate, or total homocysteine plasma levels in kidney transplant patients.
Winkelmayer
Wolfgang C
WC
The Division of Pharmacoepidemiology and Pharmacoeconomics, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
Skoupy
Sonja
S
Eberle
Corinna
C
Födinger
Manuela
M
Sunder-Plassmann
Gere
G
D000328:Adult; D000368:Aged; D000483:Alleles; D003430:Cross-Sectional Studies; D005260:Female; D005492:Folic Acid / Q000097:blood*; D005787:Gene Frequency; D005838:Genotype; D006579:Heterozygote; D006710:Homocysteine / Q000097:blood*; D006720:Homozygote; D006801:Humans; D016030:Kidney Transplantation / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D014155:Transcobalamins / Q000235:genetics*; D014805:Vitamin B 12 / Q000097:blood*
D014155:Transcobalamins; D006710:Homocysteine; D005492:Folic Acid; D014805:Vitamin B 12