In my country it is legal to abort just because you don't want the kid, but illegal to abort for a certain specific reason (the parents not wanting a girl). This is because people might abort daughters if they are poor and think that girls are less likely to get jobs.

I feel that the Down's Syndrome case is similar. There are people with Down's Syndrome who lead happy lives, and genetically 'normal' people who lead miserable lives. So of course a mother has the right to abort a foetus. But I fear that if we normalise aborting children on genetic grounds, that could lead to eugenics.