Genetic polymorphisms in the transforming growth factor beta-induced gene associated with BMI

Abstract

In an effort to identify genetic polymorphisms in potential candidate genes for type 2 diabetes mellitus (T2DM), we have sequenced the transforming growth factor beta-induced gene (TGFBI), and examined the association with T2DM and diabetic phenotypes in a Korean T2DM study (775 T2DM patients and 316 normal controls). Twenty-eight polymorphisms were identified in TGFBI. Although no significant associations were detected with the risk of T2DM, one SNP in intron 16 (c.2011+137C>T) and one SNP in the 3' untranslated region (UTR) (c.2589T>G), showed significant association with the levels of insulin and body mass index (BMI) among nondiabetic controls. The lower insulin and BMI were observed in individuals who carry one or two copies of minor alleles than others. For example, the highest BMI (24.21 kg/m(2)) in individuals with homozygote major alleles (T) of c.2589T>G (n=99), the intermediate BMI (23.68 kg/m(2)) in individuals with heterozygote alleles (n=156), and the lowest BMI (22.69 kg/m(2)) in individuals with homozygote minor alleles (G) (n=57, P=0.005) were observed. The present study provides, for the first time, information about genetic polymorphisms in TGFBI and positive associations of those polymorphisms with levels of insulin and BMI in the Korean population.