May 21, 2020
Genetics and Heredity
Question from Visalia, California, USA:
My husband and I are healthy. We had three children, two of whom have type 1. Our oldest child, who does not have type 1, has rheumatoid arthritis and has a two-year-old that was just diagnosed with type 1. What are the chances of two healthy people having all three of their children diagnosed with autoimmune diseases and then my daughter having a child diagnosed with type 1 diabetes? How does this happen when both my husband and I have no autoimmune diseases?
It is difficult to speculate without very specific genetic information on all your family members. I would assume that you and/or your husband have some genetic characteristics that allow for higher risk for these autoimmunopathies that you have in family members. i would assume that they are the higher rather than lower risk factors and then, we believe, something else (like chemicals from plastics, pollution, etc.) or some specific virus then sets off these risks to allow diabetes, RA, thyroiditis, lupus, etc. We don’t know as much about the specifics of this but the general concept seems valid with current information. We also don’t have very specific ways to intervene or provide protection under such circumstances but there has been some research looking to identify the triggers in susceptible other members of a family. Using some genetic HLA markers, watching antibody monitoring results all have been tried. You may want to talk to the diabetologists working with your family members to see if they could recommend some of these studies if anyone is interested in getting screened and participating in such important, but still early, research efforts. The best nonspecific protection so far seems to be opting for exclusive breast feeding for the first 12 months of life since there seems to be something protective that is passed along in breast milk than in cow’s milk. Our first idea that there was something negative in cow’s milk does not seem to be correct; staying away from early solid foods may also be a helper since that obviously also goes along with exclusive breast milk exposure during that first year.