Polyglandular autoimmune syndrome

I was reading in the Joslin website, and I came across this blurb:

"About 1 in 7 people with type 1 has a condition known as type 2 polyglandular autoimmune syndrome. In addition to type 1 diabetes, these people have thyroid disease, malfunctioning adrenal glands and sometimes other immune disorders. For those with this syndrome, the child's risk of having the syndrome, including type 1 diabetes, is 1 in 2, according to the American Diabetes Association (ADA)."

Surprised, because I have both thyroid disease as well as Type 1. No one has ever mentioned this to me before, including the genetic counselor I saw several years ago. The part that scared me is that children of people with this have a 50% chance of getting Type 1, rather than the 1-3% I was quoted by a genetic counselor (based on my gender, age, and age of dx).

I feel a little anxious about this. Am i overreacting? The assertion that this occurs in I in 7 Type 1's is kind of a lot of people. Is anyone familiar with this? Might this explain why some families have lots of Type 1's, while others have none?

Thanks for you input!