Look at the world. There are countless abnormal, weird children.
Are they all suffering? Whats the issue then? The issue is people
who think they can decide whether the child would be happy or
suffering. You cant decide for them, your responsibility is to give
life to them, give them the best you can, whether they are happy or
not, its not up to you. Even normal kids suffer and are unhappy,
why shouldnt these 'abnormal' ones, be given a chance at
life?
I have a fren who has a mentally retarded daughter, to them
initially, its a pain but as they see her grow up, learn to do
simple things, they found her to be the joy of their lives. Its all
in the perspective.