My son has t1. My mother-in-law has Hashimoto's Thyroiditis (autoimmune). When first diagnosed, I read in a book that besides of all the possible causes (because they just don’t know), it said that the type of disease (autoimmune) is hereditary not necessarily t1 diabetes, so genes are probably a factor. We learned that thing about milk also (body being confused between a protein that is like insulin in the milk and the body thinking that the person’s insulin is the foreign one).
I asked his doctor the other day, if we do the test to know if we could get the disease, does it mean that we will necessarily develop that disease and she said no.
So, I’ll go with aliens also!