My logic may be flawed, I certainly don't claim perfection in any way, shape or form, but from my personal point of view... Aren't humans, and particularly our children, supposed to be valued above the likes of animals? Nearly every single person here would be all but singing from the rooftops in disgust with regard to the selfishness of an animal breeder who dared to knowingly produce animals with debilitating, known inheritable diseases. "How could you do such a thing, knowing that those innocent puppies will face a life of pain and likely die an early death?" Sound familiar? Yet, when it comes to our own human children, it's perfectly ethical and acceptable to knowingly and willingly produce a human child that will suffer?
Yes, nearly everyone suffers at some point in their lives, but I for one think that there is a massive difference between possibly passing on such and such illness that you don't know for sure that you even carry, and knowing you're almost certainly going to pass on a disease that WILL cause your child to die an excruciatingly painful, early death. And, yes, I will sit here and judge parents who have their first child with a disease like Cystic Fibrosis, and then decide to continue having more after they knew they carried it, and knew their odds for producing another child with that disease. And for what? Because that child "might" be a good person and do wonderful things in life? Everyone wants to think that their children are nature's gift to our planet, and nobody wants to hear words like "genetically defective." That's why we have PC terms like "special," and "handicapable."
Regardless, I do and always will support the right of the parent or parents to make that decision for themselves and their own children, but it's my right to think that some of those choices are selfish.