My great grandma had lupus, her sister had MCTD, my grandmother has lupus, one of her sisters died from lupus induced kidney issues, 2 of her other sisters have serious health issues that are lupus like, my mother has fibromyalgia, her sister also has fibromyalgia, I have lupus, fibromyalgia, and RA (actually more see my signature), my little sister is showing signs of a problem, my oldest daughter has raynauds (she is 14).
There was a study for which I submitted a genetic sample, my family didn't choose to participate but I am sure there are other studies.