Associated Press informs that Dr. Sanders from the Evanston Northwestern Healthcare Research Institute has undertaken a study involving 1,000 pairs of gay brothers aimed at finding genetic clues for homosexuality. Previous studies haven't been taxatively concluding about any, so to call, "gay gene" but previous research showed that homosexual brothers shared certain genetic markers in their X chromosome, obviously transmitted by their mother. Sanders and other researchers believe that it's more likely to be several genes interacting together, while some scientists say that homosexuality could possibly depend on activation of some genetic markers via mother-supplied hormones around the 3rd month of pregnancy.
Homosexuals have a double stand towards genetic causes of homosexuality, proven or imaginary: on one hand, there would be much easier that courts and laws be issued against discrimination if homosexuality is eventually proven to stem from genetic causes; in the same way that skin, eye, or hair color. But on the other hand, some foresee that if such causes arise and are acutely determined, people would be able to choose whether to raise or not raise a foetus that would become a homosexual person.