New Research Reveals Type 1 Diabetes May Develop Through Different Genetic Pathways

Type 1 diabetes looks different in different people. Some develop symptoms quickly in childhood; others progress more slowly. Some have one autoantibody first, others have a different one. For decades, researchers have noticed these differences but haven't fully understood what causes them.

Now, a new study published in Diabetologia suggests the answer may lie in genetics. By examining which autoantibodies appear first, researchers discovered that type 1 diabetes may actually progress through at least two distinct genetic pathways—each shaped by different genes and biological processes.

The study focused on two common first-appearing autoantibodies: GADA and IAA. These names refer to antibodies the immune system produces against insulin-producing beta cells. The researchers used genetic markers related to HLA types—immune system proteins that influence which autoantibody develops first.

By analyzing data from over 9,000 people with type 1 diabetes and more than 14,000 without the condition, researchers found that people whose disease is associated with GADA had a different genetic profile than those whose disease is linked to IAA. The genetic overlap between these two groups was only moderate, suggesting they may not be developing the same disease in the biological sense.

One key finding involved the IL2 gene. This gene had a significantly stronger effect on type 1 diabetes in people on the IAA pathway compared to those on the GADA pathway. Other genes, like TAGAP and KLRG1, showed different patterns across the two groups.

This discovery is important because it suggests that researchers studying type 1 diabetes as a single disease may be missing critical details. The genes that increase risk—and the biological processes they control—may vary depending on how someone's immune system first attacks beta cells.

This research doesn't change how type 1 diabetes is diagnosed or treated today. However, it opens new questions about whether different prevention or intervention strategies might work better for people on different genetic pathways.

Understanding these distinct pathways could eventually help researchers predict who is at highest risk and why their disease develops the way it does. It may also explain why some people respond differently to the same treatments, and could guide future studies toward more personalized approaches to understanding and managing type 1 diabetes.

Source: Diabetologia. Evidence type: PubMed indexed literature. Type1Cure is an information and intelligence hub, not a medical advice service. This article summarizes published research and does not provide diagnosis, treatment, or personal medical guidance. Always talk to your own care team before changing anything about your Type 1 diabetes management.