Association analysis of v-AKT murine thymoma viral oncogene homolog 1 (AKT1) polymorphisms and type 2 diabetes mellitus in the Korean population

Abstract

V-AKT murine thymoma viral oncogene homolog 1 (AKT1) is an important downstream target of the insulin-signaling pathway and may be an important regulator of pancreatic beta cell growth. This study investigated the association of theAKT1 gene with susceptibility to type 2 diabetes mellitus and its related traits. By sequencing theAKT1 gene in 24 unrelated individuals, we iden-tified 32 genetic variations including 30 single nucleotide polymorphisms and 2 deletions. For the association analysis, we selected seven single nucleotide polymorphisms (rs10138227, −726G>A; rs3730358, +12574C>T; rs2494737, +12656T>A; rs2498796, +15761T>C; rs2498799, +19087 A>G; rs2494732, +19789G>A; rs3803304, +19835G>C) based on minor allele frequency (>0.05) and linkage disequilibrium status. The study included 483 type 2 diabetes patients (206 men and 277 women with mean age 64±2.8 years and mean age at onset 56 ± 8.1 years) and 1,138 non-diabetic control subjects (516 men and 622 women with mean age 64 ±2.9 years). Two single nucleotide polymorphisms (rs2498796, +15761T>C and rs2494732, +19789G>A) were found to be associated with risk of type 2 diabetes mellitus, and showed an increased risk of type 2 diabetes mellitus in a recessive model (OR=1.343, 95% CI 1.021–1.765,p=0.035 and OR=1.534, 95% CI 1.058–2.225,p=0.024, respectively). These SNPs were also associated with diabetes-related traits such as levels of fasting blood glucose and hemoglobin A1c. In addition, type 2 diabetes mellitus patients who also have dyslipidemia or high blood pressure showed significant association with single nucleotide polymorphisms in AKT1 when compared with healthy controls. These results indicate that genetic variation in AKT1 influences the development of type 2 diabetes mellitus in the Korean population.