Two genes pinpointed as cause of diabetes in babies

Scientists have identified mutations in two genes that cause neonatal diabetes, a rare condition affecting around one in 100,000 births.

The study, published in Cell Metabolism, brings the total number of genes that can cause permanent neonatal diabetes mellitus (PNDM) to 20.

As with adult-onset diabetes, PNDM is characterised by a deficiency of the hormone insulin, produced by the pancreas. Added complications that can occur in PNDM include muscle weakness, developmental delay and epilepsy.

The researchers looked at the DNA of 147 people with PNDM. Of those, 110 were found to carry mutations already identified as causing the condition. For the remaining participants, the researchers looked at genes already known to affect pancreatic development in mice. This additional analysis gave genetic diagnoses to 11 out of the remaining 37 participants, showing mutations in the genes NKX2-2 and MNX1 to be the cause in five subjects.

Dr Sarah Flanagan, the paper's lead author, from the University of Exeter said the findings were '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'.

Dr Alasdair Rankin, director of research for Diabetes UK, agreed that the paper 'helps us understand how the pancreas develops'.