Type 1 diabetes is a complex disease. Scientists know that it is not caused by a single gene – there are multiple genes involved, and the differences may vary from person to person. In fact, a recent study by a TEDDY (The Environmental Determinants of Diabetes in the Young) team has identified six gene regions that may play a role in the development of type 1 diabetes (T1D).
Researchers have already found that there are two key antibodies that are present in individuals with the disease, but one typically appears before the other, and just because a person has one or both of these antibodies does not necessarily mean they will develop diabetes. These two antibodies – one that affects insulin and one that affects the enzyme that regulates insulin-producing beta cells – account for two major subtypes of the disease, and there may be more yet to be discovered.
This recent TEDDY study focused on identifying non-HLA genes because these genes are not directly linked to the immune system. Because the immune system attacks insulin-producing beta cells, HLA genes are already a prime focus, so the researchers wanted to look at a different area. The more genes that can be identified as potentially playing a role in type 1 diabetes risk, the more effective and accurate screening measures can be.
The TEDDY initiative looks at both genetic and environmental factors in diabetes to determine how they may impact one another. The international initiative is following nearly 9,000 children for 15 years. This particular study involved 5,806 Caucasian TEDDY participants due to genetic differences between ethnic groups.
In addition to examining non-HLA genes, the researchers also looked at 176,586 single nucleotide polymorphisms (SNPs), or single variations in the building blocks of an individual’s DNA. They sought to determine whether type 1 diabetes is associated with certain SNPs. They broke this down even further to look at differences in SNPs in individuals who have T1D, and those who have islet cell autoantibodies (IA). While IA is considered a risk factor, it does not always develop into full-blown T1D.
This is the first time that this type of longitudinal study has been used in conjunction with gene identification and the development of diabetes. Scientists are hopeful that by better understanding the genetic changes that occur with T1D, they can improve detection of risk factors and potentially develop new strategies for preventing or treating the disease. According to the National Institutes of Health, 1 in 300 people in the United States are affected by type 1 diabetes by age 18.
Supporting novel research that aims to prevent and cure type 1 diabetes, or improve quality of life and reduce complications for individuals living with the disease, is the aim of the Diabetes Research Connection (DRC). Though not associated with this particular project, the DRC provides funding for early career scientists to move forward with research studies on T1D and improve understanding of the disease. To learn more, visit http://diabetesresearchconnection.org.