From what I've learned is that there are usually autoimmune conditions clusters in the family over all.
Having this vunerablity to autoimmune conditions is surely to at genetic level but inheriting T1 itself is incredibly tiny in terms of probability.
I have two T2 parents (the only confirmed T2s, this has high hereditory factors esp in S.East asians which are 6 times more likely to get it if parents have it) however I'm S.east asian and yet I'm 'LADA' or adult onset T1 and no one else has it
In my family some autoimmune conditions include rheumotoid athritis, virtiligo, thyroid, hay fever, as examples. On top of that other things e.g we have thalassemia B deficiency (this is genetic) we have asthma (is this autoimmune? I'm unsure), dermatological problems, alopecia, PCOS, Endometriosis, neurological heart issue (my sister recently, the other being tested) vit D deficiency (my brother recently - he also had an op for double carpal tunnel) the list goes on and on and on...
Out of curiosity is there any other autoimmune conditon around your family?