# First Time a New Type of Diabetes Has Been Discovered

Researchers from the University of Exeter Medical School and the Free University of Brussels have discovered a previously unknown form of diabetes in infants. The cause of the disease turned out to be a mutation in the TMEM167A gene, which is responsible for the function of insulin-producing cells. The results of the work were published in the Journal of Clinical Investigation (JCI).

Diabetes that develops in children under six months of age typically has a genetic origin. More than 85% of such cases are associated with congenital DNA changes. In the new study, scientists examined the genetic material of six infants who, in addition to diabetes, exhibited neurological disorders - epilepsy and microcephaly. All participants were found to have the same mutation in the TMEM167A gene.

To determine exactly how this mutation affects the development of the disease, a team led by Professor Mirjam Cnop used stem cells differentiated into insulin-producing beta cells of the pancreas and CRISPR genome editing technology. The results showed that when TMEM167A function is disrupted, beta cells lose the ability to produce and secrete insulin. Moreover, stress mechanisms are activated in them that lead to cell death.

"Identifying the genetic changes that cause diabetes in infants allows us to understand which genes play a key role in insulin synthesis and secretion," noted Dr. Elisa De Franco from the University of Exeter. "Thanks to this study, we have revealed the function of the poorly studied TMEM167A gene and shown that it is vitally important for the normal functioning of insulin-producing cells."

This discovery helps to better understand the mechanisms of insulin formation and maintenance in the body and could become an important step in the study of diabetes - a disease that currently affects nearly 589 million people worldwide.