New Genetic Causes of Neonatal Diabetes Identified
Researchers have identified mutations in two genes that can cause neonatal diabetes, according to research published in the January 7 issue of Cell Metabolism. Both genes play a role in the development of the pancreas. The findings increase the number of known genetic causes of neonatal diabetes to 20, according to the study authors.
"Our genetic discovery is critical to the advancement of knowledge on how insulin-producing beta cells are formed in the pancreas, which has implications for research into manipulating stem cells, which could one day lead to a cure," said lead author Sarah Flanagan, PhD, Research Fellow at the Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, UK.
"We are very proud to be able to give answers to the families involved on why their child has diabetes. Neonatal diabetes is diagnosed when a child is less than 6 months old, and some of these patients have added complications such as muscle weakness and learning difficulties with or without epilepsy," Dr. Flanagan said.
"As well as shedding further light on the genetic causes of neonatal diabetes and providing answers for parents of children with this rare condition, this work helps us understand how the pancreas develops," commented Dr. Alasdair Rankin, Director of Research of Diabetes UK, which cofunded the study. "Many people with diabetes can no longer make insulin and would benefit from therapies that replace the insulin producing beta cells of the pancreas. The results of this study are critical to bringing the day closer when this type of treatment is possible," Dr. Rankin said.
Mutations in NKX2-2 and MNX1 Cause Neonatal Diabetes
The study included 147 patients with permanent neonatal diabetes whose parents were all related (ie, second cousins or more closely related). Following a systematic screen, 110 patients received a genetic diagnosis and had mutations in non-transcription factor genes that cause neonatal diabetes. The remaining 37 patients were screened for mutations in transcription factor genes important for mouse models of pancreatic development. Mutations were found in 11 unrelated patients, four of which were in one of two genes not previously known to cause neonatal diabetes (NKX2-2 and MNX1).
Of the 121 patients with a genetic diagnosis, 106 (82%) who received a genetic diagnosis had homozygous mutations, which confirms that neonatal diabetes in the children of related families is typically recessive, according to the authors.