Variants of neurogenin 3 gene are not associated with Type II diabetes in Japanese subjects

Aims/hypothesis. Neurogenin 3 (ngn3) is a transcription factor expressed in the endocrine precursor cells of the pancreas. It has recently been reported that ngn3-deficient mice show absence of pancreatic endocrine cells and die of postnatal diabetes. The purpose of this investigation was to screen for polymorphisms of the ngn3 gene and to test whether these polymorphisms are associated with Type II (non-insulin-dependent) diabetes mellitus in the Japanese subjects. Methods. We screened ngn3 gene and upstream region by direct sequencing and estimated the prevalence of polymorphisms in 197 patients with Type II (non-insulin-dependent) diabetes mellitus and 216 control subjects. Results. We identified four novel polymorphisms, Ser199Phe (596C/T), -43insCA, -983C/T and -1822G/A. In an association study the allelic frequencies of the major allele of these four polymorphisms were 0.721, 0.914, 0.912 and 0.530 in diabetic patients, respectively, and 0.694, 0.905, 0.917 and 0.537 in control subjects, respectively. Conclusion/interpretation. Mutations and polymorphisms of ngn3 gene are not significantly associated with Type II (non-insulin-dependent) diabetes mellitus in the Japanese subjects.