It's been awhile since I thought much about Peter Singer. I'd prefer not to think about Peter Singer and his brand of utilitarianism, but there it is. It doesn't go away.
The link above is to a current article on his website discussing pretty succinctly his views on infanticide for disabled babies. Oh, he is careful to point out he is not saying disabled babies are not worthwhile. He is quite logical.
In fact, he appears to say infanticide is OK because it is logical.
Anyway, he then argues a slippery slope (it appears to me to be a slippery slope, but you know, I don't have any advanced degrees) that, if disabled people argue that disability is only a "difference", there will be no need for governmental and pharmaceutical and other support. Well, I suggest you read it for yourself, because thinking about Peter Singer gives me an intense headache and my stomach starts to get all quivery.
People often accuse Singer opponents of misquoting and misconstruing Singer. On the contrary. There it is. Read it yourself.