Born that way or not - the killer gene may present some unusual urges for the unfortunate person born with that gene; however, the gene isn't what makes a killer kill. And regardless of the origins of this unfortunate gene, killing ought not be esteemed with the same valor as a court sentencing to death or death by natural causes.
Likewise, regardless of whether or not someone's homosexuality is due an inborn disposition or inclination, it's morally wrong to express, promote or act on.
Everybody has temptings to do things that are not good. We ought not say that simply because someone has an urge to do something, that they ought to automatically feel good and like those potential actions are acceptable to society. What does the action contribute to society and even to the people involved.
Somehow, homosexuals have managed to find special exception from morality, from guidelines, and from fundamental and morally based laws. I can't send my girl to cub scouts or bring my wife to boot camp with me, but a homosexual has a free pass - and in all reality, an added risk and burden imposed on those who accommodate their behavior.
I'm extremely disheartened to see the BSA drop "morally straight" as a value and a protection for the boys. After three generations of BSA Scouting, I have to quit, and my boy won't be allowed to participate either. The BSA endorsement of alternative sexuality has trumped my religious identity and values. I say it's easier for a boy to deny his sexuality than for me and my boy to deny God and the values and motivations to choose the right that were instilled in us - and perhaps our innate and immutable disposition to denounce evil and to promote good.