Well put. And there is the rub! The core of the issue.
religion vs. science
Galileo's heliocentrism vs. the church's proponance of geocentrism, that the Earth was created by God, God created man, sent his son to save humanity, thus Earth was at the center of the universe.
What religion/society may call or identify as a genetic defect,
Science may call or clasify as evolution, as gene mutation over millions of years is thought to be at the center of that theory.
So, then at that point the real ethical issue becomes, bio-engineering. Science 'playing God.'
What if a parent said I want a child with blue eyes, blonde hair, and of a certain height? Would it make short, dark hair, brown eyed people less desired? Or, please 'fix' the 'gay gene' for my baby. I know those features are different than your argument regarding the procreating of a species, but still, engineering and defining what makes a defect based on something - whatever it is, societal or otherwise.
Not that I am arguing either one, just saying that we will likely soon see the day, as you said, that a 'genetic defect' proclamation/idea would end up having a negative societal impact on the human rights of homosexual persons. Which I, personally, would hate to see. :-(
