Mutations in the Coding Region of the Neurogenin 3 Gene (NEUROG3) Are Not a Common Cause of Maturity-Onset Diabetes of the Young in Japanese Subjects
- Laura del Bosque-Plata12,
- Joseph Lin6,
- Yukio Horikawa12,
- Peter E.H. Schwarz12,
- Nancy J. Cox34,
- Naoko Iwasaki5,
- Makiko Ogata5,
- Yasuhiko Iwamoto5,
- Michael S. German6 and
- Graeme I. Bell1234
- 1Howard Hughes Medical Institute and the
- 2Departments of Biochemistry and Molecular Biology
- 3Medicine, and
- 4Human Genetics, the University of Chicago, Chicago, Illinois
- 5Diabetes Center, Tokyo Women’s Medical University, Tokyo, Japan
- 6Hormone Research Institute and Department of Medicine, University of California San Francisco, San Francisco, California
Mutations in transcription factors that play a role in the development of the endocrine pancreas, such as insulin promoter factor-1 and NeuroD1/BETA2, have been associated with diabetes. Cell type–specific members of the basic helix-loop-helix (bHLH) family of transcription factors play essential roles in the development and maintenance of many differentiated cell types, including pancreatic β-cells. Neurogenin 3 is a bHLH transcription factor that is expressed in the developing central nervous system and the embryonic pancreas. Mice lacking this transcription factor fail to develop any islet endocrine cells and die postnatally from diabetes. Because neurogenin 3 is required for the development of β-cells and other pancreatic islet cell types, we considered it a candidate diabetes gene. We screened the coding region of the human neurogenin 3 gene (NEUROG3) for mutations in a group of unrelated Japanese subjects with maturity-onset diabetes of the young (MODY). We found three sequence variants: a deletion of 2-bp in the 5′-untranslated region (NEUROG3-g.-44–45delCA), a G-to-A substitution in codon 167 (g.499G/A), resulting in a Gly-to-Arg replacement (G/R167), and a T-to-C substitution in codon 199 (g.596T/C), resulting in a Phe/Ser polymorphism F/S199. These polymorphisms were not associated with MODY, thereby suggesting that mutations in NEUROG3 are not a common cause of MODY in Japanese patients.
- bHLH, basic helix-loop-helix
- HNF, hepatocyte nuclear factor
- IPF, insulin promoter factor
- MODY, maturity-onset diabetes of the young
- PCR, polymerase chain reaction
Address correspondence and reprint requests to Graeme Bell, Howard Hughes Medical Institute, the University of Chicago, 5841 South Maryland Ave., MC1028, Chicago, IL 60637. E-mail:.
Received for publication 7 March 2000 and accepted in revised form 22 November 2000.
Additional information can be found in an online appendix at www.diabetes.org/diabetes/appendix.asp.