Isolation and characterization of the human AKT1 gene, identification of 13 single nucleotide polymorphisms (SNPs), and their lack of association with Type II diabetes

Aims/hypothesis. AKT1, a serine/threonine protein kinase, is an important d ownstream target of the insulin-signalling pathway, with both anti-apoptoti c and peripheral metabolic effects. Because impaired insulin signalling is a major hallmark of Type II (non-insulin-dependent) diabetes mellitus, we c onsidered whether the AKT1 gene could be a candidate gene involved in susce ptibility of this condition. To test this possibility, we isolated and char acterized the human AKT1 gene. We also looked for single nucleotide polymor phisms in the gene and examined their association with Type II diabetes mel litus in the Ashkenazi Jewish population. Methods. Human BAG/P1 genomic libraries were screened to isolate the AKT1 g ene. To obtain structural information and the sequences of the exon-intron boundaries, BAG/P1 clones were directly sequenced, Identification of single nucleotide polymorphisms was done by polymerase chain reaction of each exo n, followed by denaturing high performance liquid chromatography. Six singl e nucleotide polymorphisms were genotyped in Ashkenazi Jewish patients with Type II diabetes mellitus and in control subjects. Results. The human AKT1 gene was at least 24.6 kb in length and comprised 1 4 exons. Altogether 13 putative intragenic single nucleotide polymorphisms, with minor-allele frequencies ranging from 0.011 to 0.354, were identified . The allelic and the genotypic frequencies of 6 single nucleotide polymorp hisms were the same in diabetic patients and in control subjects. Conclusion/interpretation. The results of our studies show that the AKT1 ge ne is not a major contributor to susceptibility to Type II diabetes mellitu s in Ashkenazi Jews.