icon-nav-help
Need Help

Submit your question to our team of health care professionals.

icon-nav-current-questions
Current Question

See what's on the mind of the community right now.

icon-conf-speakers-at-a-glance
Meet the Team

Learn more about our world-renowned team.

icon-nav-archives
CWD Answers Archives

Review the entire archive according to the date it was posted.

CWD_Answers_Icon
September 9, 1999

Genetics and Heredity

advertisement
Question from a physician in Belgium:

I am 48 years old and have had Type 1 diabetes since I was 33 years old. In 1985 my HLA antigens were determined: DR4, DR7.

In 1997 my oldest son (born in 1981) went for one year to the USA as an exchange student and I could persuade him to determine his HLA antigens: both DR3 and DR4 were negative. In March 1999 we determined the HLA antigens of my youngest son (Born in 1983): DR2,7; DQ1,2; DR51,53. Can you answer the following questions for me:

Do I have to make new HLA determinations?
If not, what is the possibility that my children will develop Type 1 diabetes?

As what I know about there is a problem with DR7, my oldest son should have the same probability as the normal population. My youngest son who has DR7 is at more risk. What risk? Can you put a percentage on it?

Thank you for your information. If possible, give me the references of review articles about genetics in diabetes.

Answer:

From: DTeam Staff

The overall risk for a child of a father with Type 1A (autoimmune) diabetes is between 5 and 7%. It is a little lower if the mother is the proband. Since your eldest son is DR3/DR4 negative, you are right in supposing that his risk will be essentially that of the population as a whole; that is, about 20/100,000 per annum for the first two decades of life and steadily decreasing thereafter.

We had a little difficulty in deciphering the HLA data on your younger son; but DR2 is protective and DR7 is neutral if that interpretation is correct. In neither case then would it be worth following antibodies or considering enrollment in the Europaean ‘ENDIT’ study of nicotinamide.

For further reading you might like to look at George Eisenbarth’s book on Type 1A Diabetes which you can see at www.uchsc.edu/misc/diabetes/eisenbook.html and more particularly at www.uchsc.edu/misc/diabetes/exch7.html, and of course you can spread the search much wider in PubMed.

DOB