If such genetic matter that was a behavioral determinant in fact was discovered and along with that discovery a way to neutralize it, I would imagine probably the "Gay" officialdom (organizations, spokespeople, famous Congressmen) would SOLIDLY be 100% against its use and would lobby hard against any medical action that would negate this characteristic.
All the while 60%-80% perhaps of rank and file homosexuals, including those even in 'movement leadership' would probably seek private and aggressive ways to indulge in treatment to cast off their homosexuality forever. At the end of the day I think they would have to be honest with themselves and choose the way out that would liberate them of all of the darkness and suffering. Just theorizin' here.....
Actually that would be a very good anonymous poll to ask a sampling of active homosexuals; if there were a way to negate their unique characteristic or 'orientation', would they embark upon that path. I imagine the true numbers (those who would respond truthfully and say that want out of that mess) would be very high and in fact would anger and embarrass homosexual officialdom and the organized 'racket' of perversion promoters.