You know what is fatal 100% of the time? Living at all.

Reproduction is not about logic anyway, it’s just a very common and fundamental feature of life. People who are disabled or fatally ill also have ordinary dreams, desires and human rights. Framing the issue as “these people are dooming their progeny” makes it seem like their own lives are worthless because they will die young, as if the value of human life rested on longevity. It’s quite frivolous to assume we can understand the desire to have kids of people with such diagnoses.