Indian and US Scientists Discover New Subtype of MODY Diabetes

Time of India

08-05-2025

New Delhi: In a major discovery that could transform diabetes care worldwide, researchers from the
Madras Diabetes Research Foundation
(MDRF), Chennai, and Washington University School of Medicine, St. Louis, have identified a previously unknown genetic subtype of Maturity-Onset Diabetes of the Young (MODY).
The study has been published ahead of print in the prestigious journal 'Diabetes', published by the American Diabetes Association.
This breakthrough reveals a novel disease mechanism linked to the ABCC8 gene, which plays a key role in insulin production in the pancreas. The newly discovered MODY subtype arises from Loss of Function (LOF) mutations in this gene — a sharp contrast to the Gain of Function (GOF) mutations previously associated with this gene in other forms of diabetes.
Prof Colin G Nichols, the lead researcher of this work from Washington University School of Medicine, St Louis, Missouri, USA states: 'Usually ABCC8 mutations work through Gain Of Function (GOF) mutations which lead to enhanced ABCC8 protein activity. This can occur in neonatal period when it is known as Neonatal Diabetes. In adults it occurs as ABCC8 MODY or MODY 12). Through our collaborative work with MDRF, using various experiments in the laboratory, we were able to show some novel mutations in the Indian patients with MODY which occur as Loss Of Function (LOF)."
"LOF mutations, abolish or reduce the activity of protein and they normally lead to
Congenital Hyperinsulinism
(CHI) which presents as persistent low blood glucose levels (hypoglycemia) in childhood. These patients seem to have had CHI earlier but crossed over to the opposite condition, of high blood sugar (diabetes) in later life. This is the first demonstration of this mechanism in a MODY subtype to our knowledge," Prof Nichols added.
The research involved in-depth genetic and functional studies of Indian patients clinically diagnosed with MODY. It was spearheaded in India by Dr. Radha Venkatesan, Executive Scientific Officer and Head of Molecular Genetics at MDRF, who called the discovery a "significant advancement in understanding the functional dynamics of potassium ATP (K-ATP) channels in pancreatic beta cells."
Dr. Venkatesan explained that this subtype behaves differently from other well-known forms of MODY, such as MODY 3, MODY 1, and MODY 12, all of which typically respond well to sulphonylurea medications. However, individuals with this new subtype do not respond to such drugs, emphasizing the need for personalized treatment strategies.
Dr. V. Mohan, Chairman of MDRF, said, 'This is a major milestone in diabetes research from India. The discovery highlights the importance of genetic testing for precision diagnosis. By identifying these distinct subtypes of MODY, we are paving the way for tailored therapies and improved outcomes for patients who would otherwise be misdiagnosed or inadequately treated.'
MODY is a rare, inherited form of diabetes caused by mutations in a single gene and usually manifests in adolescence or early adulthood. To date, 13 MODY subtypes have been recognized.
This newly identified variant challenges conventional understanding of how MODY develops and points to the need for broader access to genetic screening, particularly in low- and middle-income countries where such diagnostics are often unavailable.
Researchers say the finding could guide the development of
novel diabetes drugs
targeting this specific genetic pathway and stress the importance of functional studies alongside genetic testing in unraveling complex diseases.