Understandable. Again, something in society I just don't agree with, but it's a thing. The whole 'denying someone's insurance based on pre-existing conditions' is ludicous. It's not like they can just 'stop' being sick. Medical is expensive, especially in the US, but that's the whole point behind insurance. I'd rather pay an expensive premium than owe my entire medical bill regardless; however, insurance companies want to take the coverage away entirely.
Regardless, people already use this method for tracking known conditions like Parkinson's and Alzheimer's in their family lines. I don't see any reason to deny them the ability for such a tool, so long as it's managed correctly.