The gay gene , 19th. OUT DOWN ON THE FARM, 30th. The gay gene in The Pink Paper , 19th. Well, it all started in 1993 when Dean Hamer of the US National Cancer Institute studied 40 pairs of gay brothers and found that many gay men carried an identical version of a small segment of the X chromosome's DNA known as Xq28. The family histories of 114 gay men showed their brothers, maternal uncles and maternal male cousins were more likely to be gay.
Men get an X chromosome from their mother, and a Y from their father.
Because the genes on a son's X chromosome are an extremely variable combination of the genes on the mother's two Xs, there are major differences between brothers' genetic structures. But similarities in Xq28s between those who are gay, scientists claim, is unlikely to be coincidental. Some suggest the X chromosome is also responsible for the smaller numbers of dykes. No, but they think they have isolated the genetic basis of male homosexuality. Research is ongoing as to the existence of a lesbian gene.