National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Diabetes mellitus type 1

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My wife's grandpa died of type 1 diabetes. My wife's younger sister has been diagnosed with type 1 diabetes at age 23. I'm worried that this will affect my kids. What are the possibilities or chances that my kids and their generations will have type 1 diabetes?

The following information may help to address your question:


Is diabetes mellitus type 1 inherited?

Diabetes mellitus type 1 (DM1) itself is not inherited, but a predisposition to developing the condition can run in families. While some people with a family history of DM1 may be at an increased risk, most will not have the condition.

While the exact cause is not known, some genetic risk factors have been found. The risk of developing DM1 is increased by having certain versions (variants) of genes, which belong to a family of genes called the human leukocyte antigen (HLA) complex. HLA genes have many variations, and people have a certain combination of these variations, called a haplotype. Certain HLA haplotypes are associated with a higher risk of developing DM1, with particular combinations causing the highest risk. However, these variants are also found in the general population, and only about 5% of people with the gene variants develop DM1. Other genes, as well as a variety of other factors, are thought to influence the risk for DM1 also.[1]

Because there is no specific inheritance pattern associated with DM1, it is difficult to predict whether another family member will develop the condition. Generally, the risk is higher if a parent or sibling is affected. In some cases, genetic testing can be done to determine if someone who has a family history is at increased risk of developing the condition.[2] 

More information can be found on the America Diabetes Association's Web site, which has an article entitled Genetics of Diabetes.

People with specific questions about genetic risks to themselves or family members should speak with their health care provider or a genetics professional.
Last updated: 4/25/2014

How can I find a genetics professional in my area?

To find a medical professional who specializes in genetics, you can ask your doctor for a referral or you can search for one yourself. Online directories are provided by the American College of Medical Genetics and the National Society of Genetic Counselors. If you need additional help, contact a GARD Information Specialist. You can also learn more about genetic consultations from Genetics Home Reference.
Last updated: 12/6/2017

We hope this information is helpful. We strongly recommend you discuss this information with your doctor. If you still have questions, please contact us.

Warm regards,
GARD Information Specialist

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  1. Type 1 diabetes. Genetics Home Reference. March, 2013; http://ghr.nlm.nih.gov/condition/type-1-diabetes. Accessed 4/25/2014.
  2. Type 1 diabetes. Mayo Clinic. January 23, 2013; http://www.mayoclinic.org/diseases-conditions/type-1-diabetes/basics/risk-factors/con-20019573. Accessed 4/25/2014.