[DrPhil]

In that case, how can we trust any "warning signs" or predispositions for any condition?

There are people who do not have biological children because of warning signs and predispositions for certain conditions. There are also people who insist on having biological children despite (and sometimes as a result of) warning signs and predispositions for certain conditions. I am in favor of the former rather than the latter but people should do what works for whomever (the biological parents? The future offspring?). I'm also pro-choice so people need to figure out what they are willing to endure based on whatever information available.