I was dx at age 11 - the only T1 in my family. My son was dx at age 5, he is now 9. I have another son who is non-D and is 6. I caught my son fairly early on - he was never hospitalized. His random glucose midmorning was in the 300’s (18ish for those outside of the USA). I believe there is a genetic link to autoimmune disorders and which autoimmune disorder(s) you get is the “luck of the draw” I guess you could say. They don’t know what triggers any of the autoimmune disorders out there, but lots of research points to genetics together with some sort of environmental trigger.
In my immediate family I have T1, my sister was dx with Hashimoto’s (hypo thyroid) about 6 years ago in her 40’s. We cannot really look at our family history because they are all in Europe and we can’t go back further than one generation (long story). On my husband’s side his sister was dx with celiac’s (another autoimmune disorder) a couple of year’s ago when she was 40. He has 9 siblings and she’s the only one with an autoimmune disorder. So perhaps the chances would be greater because the genetics lie on both sides for my children.
Here is a link for some genetic and statistical info. I don’t know how up to date it is though. There has been so much research going its hard to keep up with it all.
http://www.genetichealth.com/DBTS_What_Is_Type_1_Diabetes.shtml
I think its natural to be paranoid, and I think it so very important not to pass that paranoia on to my non-D son. I ask him to pee on a stick every now and then (I usually buy the combo stick which measures sugar and ketones). They are cheap and non-invasive. I think because we are so aware of the symptoms that our children will not get to that point of being so sick of being hospitalized. I never put my non-D son in the Trial Net Study because I don’t want to have to worry about “when” if there are autoantibodies present and I also don’t want to be fooled if the autoantibodies are not present, because they say even if they are not present right now, they may be later. I also don’t want to subject him to the needle pokes of which he is mortified. (Which I think is kind of odd, because he has no problem giving me injections or finger pokes. I guess its not him feeling the poke.)
This is purely just me though and I think its fine if someone else goes ahead with the testing.