From Tom Schreiner's article A New Testament Perspective on Homosexuality:
Even if some sins could be traced to our genetics, it would not exempt us from responsibility for such sins. The Scriptures teach that all human beings are born into this world as sons and daughters of Adam, and hence they are by nature children of wrath (Eph. 2:3). They are dead in trespasses in sins (Eph. 2:1, 5), and have no inclination to seek God or to do what is good (Rom. 3:10–11). We come into the world as those who are spiritually dead (Rom. 5:12, 15), so that death reigns over the whole human race (Rom. 5:17). Indeed, human beings are condemned by virtue of Adam’s sin (Rom. 5:16, 18). Such a radical view of sin in which we inherit a sinful nature from Adam means that sinful predispositions are part of our personalities from our inception. Hence, even if it were discovered that we are genetically predisposed to certain sinful behaviors like alcoholism or homosexuality, such discoveries would not eliminate our responsibility for our actions, nor would it suggest that such actions are no longer sinful. The Scriptures teach that we are born as sinners in Adam, while at the same time they insist we should not sin and are responsible for the sin we commit. We enter into the world as slaves of sin (Rom. 6:6, 17), but we are still morally blameworthy for capitulating to the sin that serves as our master.
HT: Justin Taylor