ABCG5 and ABCG8 gene polymorphisms in type 2 diabetes mellitus in the Turkish population

The aim of the present study was to investigate the relationship between ABCG5 and ABCG8 gene polymorphisms and plasma lipid concentrations in Turkish patients with type 2 diabetes mellitus.

Included in this study were 80 patients with type 2 diabetes and 73 healthy controls. Two selected single nucleotide polymorphisms in ABC transporter genes, ABCG5 (rs6720173) and ABCG8 (rs4148211), were genotyped by using the polymerase chain reaction-restriction fragment length polymorphism technique.

The rate of having the ABCG8 AA genotype (p=0.001) was significantly higher in the patients than in the control subjects. Correspondingly, the rates of having the AG genotype (p=0.001) and the G allele (p=0.001) were significantly lower in the patients than in controls. Upon comparing the groups regarding ABCG5, the frequencies of occurrence of the GG genotype (p=0.031) and G allele (p=0.003) were considerably higher in patients than in control subjects. In the patients, the rates of having the CC genotype (p=0.003) and the C allele (p=0.031) were also significantly lower than those in control subjects. There was no significant difference between G5 and G8 polymorphism and lipid levels in the study groups. The ABCG8 AA genotype carriers had higher triglyceride (p=0.045) and very low-density-cholesterol (p=0.045) levels than the ABCG8 GG genotype carriers in all study populations.

These results indicate that the AA genotype for ABCG8 and the GG genotype and G allele for ABCG5 are risk factors for diabetes. This study reveals the first data concerning the ABCG5 and ABCG8 gene polymorphisms in Turkish patients with diabetes.