(continued)

"Morally Unacceptable"
Not that people haven't tried to stop it. In October 2002, the Nuffield Council on Bioethics, a leading UK-based medical science think tank, released a 258-page report called Genetics and Human Behaviour: The Ethical Context. In it, the council warned of dire implications of widespread testing and called for a ban on tests to determine behavioral traits such as intelligence, sexual orientation, and personality in unborn babies. "We take the view that the use of selective termination ... to abort the fetus on the basis of information about behavioural traits in the normal range is morally unacceptable," the report concluded.

Conservatives opposed to both abortion and homosexuality will have to ask themselves whether the public shame of having a gay child outweighs the private sin of terminating a pregnancyAnd at a congressional hearing last July, representatives from the Genetics and Public Policy Center at Johns Hopkins blasted the government's laissez-faire response to this new wave of genetic testing and called for immediate action. "I don't think there is awareness of the degree to which the government does not oversee genetic testing," center spokeswoman Gail Javitt says.

None of it seems to bother Holt Vaughan, president of Texas-based testing outfit Health-CheckUSA. Vaughan believes that parents are entitled to information about the genetic future of their unborn children, provided they get counseling to help them avoid rash decisions. Asked if he'd market a "gay gene" test, Vaughan doesn't miss a beat: "It's a very hypothetical question," he says. "But if our medical director looked at it and believed it was a credible test, then yeah!"

Know the Code
The role of DNA in determining sexual orientation has been coming into focus since 1979. That's when a landmark study conducted at the University of Minnesota found that identical twins who had been separated at birth and raised apart were likely to share a wide range of personality traits not often attributed to genetics. Building on those findings, in 1991 Michael Bailey and Richard Pillard found that identical twins were much more likely to both be homosexual than were fraternal twins or non-twin or adopted brothers. Their discovery—as well as the completion of the Human Genome Project in 2003—informed a growing scientific consensus that homosexuality was at least partly biological.

No one has come closer to finding specific genetic markers for it than Dean H. Hamer, Ph.D., Chief of the Section on Gene Structure and Regulation in the Laboratory of Biochemistry of the National Cancer Institute. Hamer is, as Discover magazine put it in 1997, the nation's premier "big gene hunter."

In 1996, Hamer was able to connect neurotic behavior in humans to the gene responsible for our processing of serotonin, a brain chemical that affects impulsiveness and anxiety. Clearly not averse to controversy, in 2004 Hamer published The God Gene: How Faith is Hardwired into Our Genes (Doubleday), in which he traced feelings of spiritual transcendence to a single gene called VMAT2. Needless to say, religious fundamentalists did not rejoice.

But none of his previous work generated as much attention—or outrage—as his 1993 discovery of the "gay gene." Working with noted British neuroscientist Simon LeVay (who went on to find differences in the brains of gay and straight men), Hamer made his groundbreaking discovery by accident. He had started out looking for the genetic root of Kaposi's sarcoma, an otherwise rare cancer that kills many AIDS patients. His cancer search was unsuccessful, but as Hamer was examining sets of genes in 40 pairs of homosexual brothers, he found five markers that revealed the Xq28 chromosome region as the site of the genetic code for homosexuality.

Since he published his report in the July 1993 issue of Science, Hamer has faced a barrage of criticism. N.E. Whitehead, coauthor of My Genes Made Me Do It!, blasted Hamer for restricting his sample to gay men, arguing that the results might have been different if he'd included a control group drawn from the general population. Religious groups protested, insisting heterosexuality is the biological norm, and deviance from that norm is learned, not inherited. Even many psychologists were skeptical. But so far, no one has offered convincing evidence to refute his claims.

Rainbow's End?
Hamer's findings hold out the ethically-dubious promise that parents who are no friends of Dorothy may one day be able to discard suspiciously swishy embryos. By examining a string of genes in the Xq28 region, Hamer says he can predict with unprecedented accuracy whether a child is likely to be gay. It's certainly not foolproof, but access to such information would no doubt inspire many parents to abort an embryo whose results suggested a high probability of homosexuality.

Though he is gay himself, Hamer seems curiously unconcerned about the potential implications of his research. "People are often afraid that finding [a gay gene] will lead people to rethink homosexuality as a disease," he says. He doesn't share that fear, and argues that few people will make life-and-death decisions about their unborn babies based on single traits.

But as it turns out, they already are. A survey of 415 genetic labs conducted by the Genetics and Public Policy Center (GPPC) found that 42 percent of them had used genetic testing to help parents select the gender of their children. Labs are also regularly tossing embryos with genetic predispositions to colon cancer or Alzheimer's. While infants born with these genes are far from certain to come down with these diseases, many prospective parents opt to play it safe.

Gay rights advocates worry that genetic testing puts homosexuality on the same level as such diseases, pointing it down the road to the same goal: elimination. Even if it were possible to genetically erase homosexuality, however, doing so would come at a social price. Glenn Wilson, a reader in personality at the Institute of Psychiatry in London and coauthor of Born Gay: The Psychobiology of Sex Orientation, argues that the same genes that influence homosexuality are crucial to the expression of valued behavioral traits, such as verbal fluency and mastery of spatial relationships. (Translation: It's not entirely accidental that your Uncle Jimmy has a knack for show tunes and interior design.)

"If you did ever succeed in wiping out homosexual orientation, you would also remove many positive traits that are good for humanity as a whole and also good for individuals," Wilson adds. Thus, eradicating homosexuality, even if it could be done without the destruction of a single organism, "would be ethically indefensible."

Ethics, however, might not dissuade the many who continue to view man-on-man action as the ultimate threat to Western civilization. "You put this stuff in the hands of a real homophobe," warns Martin Munzer, president and CEO of CyGene, "and that's when it gets scary."

But if genetic testing could become a weapon for those hoping to wipe out homosexuality, one trend suggests it could also be a tool to preserve it. In the GPPC survey cited above, three percent of labs reported having used genetic testing to help parents who wanted to conceive a child with a disability, such as deafness. Last year, in a much-publicized case in New Jersey, a couple with dwarfism sought to use PGD to conceive a baby that shared their phenotype. They ultimately chose instead to adopt.

While the press attacked the couple bitterly, others were more sympathetic. "These people had lived with this disease all their lives, and they just wanted to have a kid who looked like them," says Jamie Grifo, M.D., Program Director for New York University's Reproductive Endocri-nology Division and professor of Obstetrics and Gynecology at NYU medical school.

Grifo, an early proponent of genetic research, has performed PGD procedures for a decade and says he has no qualms about helping parents have babies with certain traits. "Personally, I believe that people should be allowed to make their own decisions. I believe in the right of the individual. They're not going to harm the species."

And, if they are, it's probably too late to do anything about it with the gene genie already out of the bottle. "We're at the advent of a brave new world here," says Munzer. "We don't know where it's going to go, but there's no stopping it now."

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