What Is Monogenic Diabetes?
Reviewed by CDE Mehandi Sharma · Updated
Monogenic diabetes is diabetes caused by a change, or variant, in a single gene.
That makes it fundamentally different from the two common types. Type 1 is autoimmune — the immune system destroys the cells that make insulin. Type 2 involves the body resisting insulin while production gradually falls. Monogenic diabetes is neither. A single gene is not working as it should, and that gene affects how insulin is made or released.
Researchers have identified more than 20 genes that can cause it. It is uncommon — around 1 to 5 of every 100 people with diabetes have a monogenic form.
It divides broadly into two groups. MODY usually appears in teenagers or young adults, with relatively stable blood glucose. Neonatal diabetes appears in the first six to twelve months of life and is rarer still, affecting about 1 in every 90,000 babies.
The single most important consequence is treatment. Because the underlying fault differs from Type 1 and Type 2, the right treatment often differs too — sometimes dramatically. Some subtypes need no glucose-lowering medicine at all. Others respond much better to a specific tablet than to insulin.
That is why identifying it matters, and why the genetic result is worth pursuing rather than accepting a label that happens to fit approximately.