Genetic manipulation?

Basically, there is a deaf couple who is using invitro fertilization and wants the right to screen and/or genetically alter their child so that s/he turns out to be deaf like them. They do not see deafness as a disability, and think that choosing a hearing child over a deaf one is absurd and a huge discrimination.

I could see where they don't see deafness as a disability. Here's what I don't get though - don't they remember all the hard things that they've had to go through because of being deaf? The discriminations and misunderstandings and awkward dating? No doubt they, as parents, would handle their children better than their parents might have. But why not adopt? Why cause an otherwise normal child to miss out on things like music and hearing the words "I love you" from their future spouse? Don't they know that they child will end up resenting them for that?

I know that I've debated several times whether or not I should even have kids because of the pain and discrimination that I've gone through with my arthritis. More than likely, if I have a daughter she will have it too. I don't particularly see the arthritis as a disability per se, because I now have a handle on it. But I can't morally ask the doctor to make sure that my child has the same extra issues that I do. That is simply cruel and unusual punishment, especially for a little fetus who doesn't have a voice here. I know that when I do have children, I will know what they are going through and I will be able to help them and be there for them because I have gone through that. But I do sincerely hope that my children do not have this, that they can be at least closer to normal than I.

Aside from all of that though, isn't this bordering on Gattaca? Are we trying to genetically engineer our children into what we want them to be without even giving them a chance to choose? What if the doctor screws up and the child ends up being able to hear, but has a terrible life-altering disease as well? One that s/he will die early from? Suffer terribly? Do we really have the right to override that child's ability to have a great and wonderful, semi-normal life, just because we want a child to be like us?

I'm sure that the couple would see my ideas as thinking that deafness is a disability though.