*Diseases which are fatal and reduce one's life expectancy drastically (e.g. Cystic Fibrosis, Huntington's etc.) are the ones I'm most against, imagine your child knowing the age that they would die- around their thirties too-it would be fucking heartbreaking
Cystic fibrosis requires both parents to be carriers of the gene and current research is looking at ways to replace/repair the gene. Before we become Hitler and decide who can breed, let's look at the future of gene therapy for these diseases. Huntington's is something I have no problem with. If I was told I had until my 50s to live, I'd do my best to make the most of my life. 50=/= 12, which would be far more cruel to a person. I could get hit by a bus tomorrow, I'm not going to crawl into my mothers womb and request a retrospective abortion because I don't get to live until the average of 77.
*Diseases which disable significantly (I can't really judge what's significant or not, but serious cases of Marfan Syndrome and Spinal Muscular Dystrophy are some examples) disallowing one from having the choice to live a healthy, average life. they don't have to be fatal but they might as well be
AFAIK, some forms of spinal muscular atrophy don't manifest until after birth and are caused by faulty genes that aren't easily tested for before birth. AFAIK, most types are autosomal recessive and require each parent to have one faulty gene which they may be unaware of. So unless you guys are proposing every person go out and get full genetic maps or whatever, idk.
who becomes responsible for the pain they've suffered? surely it's their parents? I see no one else that could be at fault
Stop speaking on behalf of these people. You don't know their pain, if any, and what do you care if the parents are responsible for the childs welfare. We can't dictate who can and can't have babies just because
we think their lives aren't worth shit.