Back to Ask the Diabetes Team Ask the Diabetes Team

From Pennsylvania, USA:

I have a 17 year old son who has Type 1 diabetes and has been under treatment for 3 years. Now my 15 year old nephew has been diagnosed as Type 1 diabetes also. We were told this condition is not inherited. Is this true? My sister (his mother) also gets gestational diabetes. Does this mean anything? My dad has Type 2 diabetes.


In Type 1 Diabetes what is inherited is a certain pattern of proteins that lie on the surface of individual cells, what is called an HLA haplotype. Depending on the details, these confer a vulnerability to diabetes; but some environmental factor, which is not understood yet, has to trigger the abnormal response of the body's immune system.

Gestational diabetes occurs when the changes in counterregulatory hormones (ones that work in the opposite direction to insulin) during pregnancy stress the normal supply of insulin. In your sister, this could indicate that she has a very mild Type 1 diabetes that may never reach the point of requiring extra insulin when she is not pregnant.

The genetics of Type 2 Diabetes are quite different from Type 1; but nowadays the dividing line in the adult years is getting a little blurred. Type 1 Diabetes has now been diagnosed in people in middle age so that depending on the age at diagnosis it is not impossible that your father has Type 1 Diabetes too.


[Editor's comment: The distinctions between Type 1 and Type 2 and Gestational Diabetes are becoming clearer as more research is done. I think that an important point to understand is that Type 1 diabetes is a specific autoimmune disorder that is now recognized as occasionally slowly progressing in adults; in the past, such patients would have been designated Type 2 ("Adult-onset diabetes") based on age; but now, with antibody studies becoming more reliable for routine use, we'll have to reassess which adults really have Type 2 diabetes, and which actually have slowly-developing-Type 1 diabetes. WWQ]

Original posting 2 Dec 96


  Back to Ask the Diabetes Team Return to the Top of This Page

Last Updated: Tuesday April 06, 2010 15:08:52
This Internet site provides information of a general nature and is designed for educational purposes only. If you have any concerns about your own health or the health of your child, you should always consult with a physician or other health care professional.

This site is published by T-1 Today, Inc. (d/b/a Children with Diabetes), a 501c3 not-for-profit organization, which is responsible for its contents. Our mission is to provide education and support to families living with type 1 diabetes.
By using this site, you agree to our Terms of Use, Legal Notice, and Privacy Policy.
© Children with Diabetes, Inc. 1995-2018. Comments and Feedback.