September 29, 2005
Complications, Other
Question from Winnipeg, Manitoba, Canada:
Autoimmune diseases run rampant on one side of my family, in all five children, although diagnosed at all different ages, type 1 diabetes included. My maternal grandfather developed type 1 at age 20, his brother at age four. The former passed away of cancer at age 73, with no significant, if any, complications. My mother was diagnosed at age nine, and she is not expected to live much longer, now, at 47 years of age. I myself was diagnosed at age two. I am now 23, and have NO detectable damage due to hyperglycemia. There is no evidence of any autoimmune disease on my maternal grandmother’s side, nor anywhere in my father’s family.
What are my chances of having some sort of genetic “protection” against hyperglycemic damage, possibly due to the large secretion of a particular enzyme or organic anti-oxidative compound? If I have no damage after 21 years of diabetes, does this mean I should not develop say, ESRF (Renal Failure)? I try to keep my A1c under 7.0 and take Omega 3-6-9 EFA supplements for inflammation due to high blood sugars and having an autoimmune disease. My control as a child was extremely poor, with A1cs over 11.0, until I was removed from my mother’s care.
Also, is it possible that there is some dominant genetic factor from my maternal grandfather in which my offspring have an almost 100% chance of developing type 1 and/or another autoimmune disease? I believe in eugenics, so I don’t really think I should have a child, but let’s say my future husband does. Is there a way to “protect” my offspring by say, marrying an Asian, who have seemingly genetic protection against type 1 (based on common HLA types). Is there a genetic counselor who could assess this type of situation?
Is genetic manipulation something you can fathom in the near future? None of the studies trying to prevent type 1 have worked and I believe, in my case, the genetic factor is dominant and eventually anything could be the trigger for type 1.
Answer:
Your questions get back to how humans inherit their predisposition to developing type 1 diabetes. The working model currently implies that we are born with a set of genes that control how our immune system works. In addition, for type 1 diabetes to occur, that has to be some additional environmental factor that stimulates the immune system into producing damage to the insulin-producing cells in the pancreas. As you suggested, there are HLA types that have higher risk for type 1 diabetes. It is not yet understood how these HLA genes particularly determine how the disease develops. It is also true that there are familial tendancies for the development of complications related to type 1 diabetes. Previous studies from twins with type 1 diabetes have shown a predisposition for complications to occur in relatives and the same is true for protection from complications. The good news for you is that if you have lived for over 20 years without developing kidney-related complications, there is a very low risk you will suffer from renal failure. The peak time for development of nephropathy is roughly 15 years. In addition, if your family members have avoided nephropathy, this is also good news. It is more difficult to prevent minor levels of neuropathy or retinopathy over a lifetime, but it appears that control really does matter and good control offers protection. As far as oxidative damage or enzymatic mechanisms, there are currently hypotheses for these factors playing a role. However, preventive therapy is not available that prevents these problems at the molecular level. In your case, there is some risk of having a child who will develop type 1 diabetes. I would suggest you speak with someone locally who has expertise in prenatal counseling who can give you a better picture of risk.
JTL
