Does type 1 diabetes run in families?

Dr. Jeanne Morrison, PhD
Family Practitioner

The risk factor for type 1 diabetes is somewhat higher if one of your immediate family members-such as a parent or sibling-has developed this condition. Research shows that certain genes can determine whether you are predisposed to type 1 diabetes. Therefore-you may want to consider genetic testing if you have a family history of type 1 diabetes. However-this type of testing is still in clinical trial stages.

William Lee Dubois
Endocrinology Diabetes & Metabolism

Maybe. We used to view Type-1 as a very lone wolf affair. Often patients had no blood relatives with the disease. Sometimes one identical twin will have T-1 and the other will not. That said, over recent decades T-1 seems to be clustering with multiple sibs and intern-generational cases. One theory is that there may in fact be a genetic component that can be passed on; but it is taking several generations to reveal itself. Recall that prior to 1922 (when insulin appears on the scene) all T-1 Diabetics died, usually before puberty.

People with a family history of type 1 diabetes do have a slightly higher risk of developing the condition. Certain gene combinations appear to increase the risk of type 1 diabetes, and environmental factors likely play a role, too. Unlike the more common type 2, type 1 diabetes is most likely an autoimmune disease in which the body mistakenly attacks the cells in the pancreas that make insulin. An infection or another trigger may bring on this autoimmune response. The tendency to develop type 1 diabetes can be inherited.
Mr. Eliot LeBow, CDE, LCSW
Endocrinology Diabetes & Metabolism

There maybe a family component but with Type I diabetes you will find that there are both genetic and environmental risk factors for developing diabetes. With the genetic component, forty percent of people in the United States carry the gene that is related to diabetes from one parent. It's called the HLA genes (human leukocyte antigen). However actually developing Type I diabetes is dependent on whether the person has duplicate HLA genes, one from each parent. 

With that said, diabetes in the family only increases one's chance of being diagnosed with diabetes by 10 to 15%. 

At this point in time there are only causal relationships between diabetes and family. One thing is clear is that 85% of those diagnosed with diabetes do not have a history of diabetes in their family.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.