I reviewed mesages today and read your question for the first time. In my case, I learned that four aunts, my mother, and a cousin (female) have thyroid/Grave’s disease. My mother had a goiter removed 50 years ago; and an aunt also. I am the only one who has had the double vision or any kind of eye surgery. So I believe there is definitely a genetic bias. And I also believe in us who have a genetic bias for it that stress can be the igniter, but that is ONY my opinion, nothing I have read in any medical literature. Its a good question that deserves further study.