Is it ethical to abort for a gay gene?

Soon genetic carriers for several genetic conditions will be in the same quandary which those who parent a child with Down syndrome find themselves according to this article in Bioedge.  Parents can eliminate embryos from a petry dish before implantation or abort a diagnosed baby for one of a number of defects. 

Within a few years, parents may be able to screen embryos and foetuses for the “gay gene”, according to a Columbia University bioethicist. Robert Klitzman, whose most recent book is Am I My Genes?: Confronting Fate and Family Secrets in the Age of Genetic Testing,

 They will be able to find out if an unborn baby has a tendency towards autism, Alzheimer's or homosexuality. Will prenatal testing which so naturally leads to abortion in the vast majority of cases when the diagnosis of Down syndrome is delivered, suddenly be seen as immoral? I was told that at a biotehics conference at the United Nations. It was stated by a Danish bioethicist that since gay people contribute to society but people with Down syndrome don't it would be immoral to abort for a gay gene. Really? Useless eaters, eh?

Parents of children with Down syndrome were told for forty years that prenatal testing with abortion was the 'cure' for Down syndrome. Very little effort was made to find treatments for the cognitive delays of Down syndrome since the 'cure' had been found. We had refused our only option, and didn't deserve another, according to scientists. What other disease do we treat by executing the patient?

During these forty years from the time he discovered trisomy 21, the cause of Down syndrome in 1959,, French geneticist Dr Jerome Lejeune was the lone researcher for a cure for Down syndrome. He was mortified that his discovery led to the death of thousands of babies with Down syndrome, and said,

“Again and again we see this absolute misconception of trying o defeat a disease by eliminating the patient! It’s ridiculous to stand beside a patient and solemnly say, “Who is the upstart who refused to be cured? How dare he resist our art? Let’s get rid of him!” Medicine becomes mad science when it attacks the patient instead of fighting the disease. We must always be on the patient’s side, Always.”