Scientists discover new gene-linked type of diabetes in babies under six months

Researchers from the University of Exeter and ULB have identified mutations in the TMEM167A gene causing a rare form of neonatal diabetes in babies under six months. Stem cell studies show the gene is vital for insulin-producing beta cells and neurons.

New Delhi: An international team of scientists has discovered a new type of diabetes in babies, under six months of age.

Some babies develop diabetes before the age of six months. In over 85 per cent of cases, this is due to a genetic mutation in their DNA.

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Using advanced DNA sequencing technologies and a new model of stem cell research the team from the University of Exeter in the UK and Université Libre de Bruxelles (ULB) identified mutations in the TMEM167A gene — responsible for a rare form of neonatal diabetes.

They found that in six children with additional neurological disorders such as epilepsy and microcephaly there was alterations in the TMEM167A gene.

“Finding the DNA changes that cause diabetes in babies gives us a unique way to find the genes that play key roles in making and secreting insulin. In this collaborative study, the finding of specific DNA changes causing this rare type of diabetes in six children, led us to clarifying the function of a little-known gene, TMEM167A, showing how it plays a key role in insulin secretion,” said Dr. Elisa de Franco, at the University of Exeter.

To understand its role, the team used stem cells differentiated into pancreatic beta cells and gene-editing techniques (CRISPR). They found that when the TMEM167A gene is altered, insulin-producing cells can no longer fulfill their role. They then activate stress mechanisms that lead to their death.

“The ability to generate insulin-producing cells from stem cells has enabled us to study what is dysfunctional in the beta cells of patients with rare forms as well as other types of diabetes. This is an extraordinary model for studying disease mechanisms and testing treatments,” said Professor Miriam Cnop, researcher at ULB.

The discovery, published in the Journal of Clinical Investigation, shows that the TMEM167A gene is essential for the proper functioning of insulin-producing beta cells, but also for neurons, whereas it seems dispensable for other cell types. These results contribute to a better understanding of the crucial steps involved in insulin production and could shed light on research into other forms of diabetes, a disease which today affects almost 589 million people worldwide.