
August 24, 2003
Genetics and Heredity
Question from Millville, New Jersey, USA:
I just found out that my great grandfather on my grandmother’s side of the family had type 2 diabetes, and my uncle (same side of the family) who just recently passed away had it as well. In addition, my daughter was diagnosed with type 1 diabetes about five years ago. Is it possible to go from type 2 to type 1 diabetes through the family tree? Is this the beginning of the generation of people with type 1? What will this information do to my daughter’s diagnosis since hers was considered to be a fluke?
I am trying to stay on top of everything. My daughter is well taken care of, and my son is showing signs of resistance (the pigmentation) but his A1c was 5.0% a year ago. What will insulin resistance do to someone with type 1 diabetes?
Answer:
Both type�1 and type�2 diabetes are to some extent inherited, but the mechanisms are quite different. Thus, there is no reason that your daughter should have the same kind of diabetes that your great grandfather and uncle had.
In all probability, she has type�1A (autoimmune) diabetes which should have been confirmed by a positive antibody test at the time of diagnosis. However, when you say that your son has evidence o insulin resistance as well as skin pigmentation (perhaps acanthosis nigricans) if he is also overweight, I would wonder if perhaps he is in the early stages of what is called the metabolic syndrome which is in fact linked to type 2 diabetes or even if he might have the type A insulin resistance syndrome. Without more detailed information, it’s difficult to elaborate on this, and I think you need to talk all this over with the endocrinologist or his/her nurse. I am sorry that its not possible to do justice to all of these possibilities in an e-mail.
DOB