October 15, 2007
Study Seeks DNA Clues on Homosexuality
By LINDSEY TANNER
AP Medical Writer

CHICAGO (AP) -

Julio and Mauricio Cabrera are gay brothers who are convinced their sexual
orientation is as deeply rooted as their Mexican ancestry. They are among
1,000 pairs of gay brothers taking part in the largest study to date
seeking genes that may influence whether people are gay.

The Cabreras hope the findings will help silence critics who say
homosexuality is an immoral choice.

If fresh evidence is found suggesting genes are involved, perhaps
homosexuality will be viewed as no different than other genetic traits like
height and hair color, said Julio, a student at DePaul University in
Chicago.

Adds his brother, "I think it would help a lot of folks understand us
better."

The federally funded study, led by Chicago-area researchers, will rely on
blood or saliva samples to help scientists search for genetic clues to the
origins of homosexuality. Parents and straight brothers also are being
recruited.

While initial results aren't expected until next year - and won't provide a
final answer - skeptics are already attacking the methods and disputing the
presumed results.

Previous studies have shown that sexual orientation tends to cluster in
families, though that doesn't prove genetics is involved. Extended families
may share similar child-rearing practices, religion and other beliefs that
could also influence sexual orientation.

Research involving identical twins, often used to study genetics since they
share the same DNA, has had mixed results.

One widely cited study in the 1990s found that if one member of a pair of
identical twins was gay, the other had a 52 percent chance of being gay. In
contrast, the result for pairs of non-twin brothers, was 9 percent. A 2000
study of Australian identical twins found a much lower chance.

Dr. Alan Sanders of Evanston Northwestern Healthcare Research Institute,
the lead researcher of the new study, said he suspects there isn't one
so-called "gay gene."

It is more likely there are several genes that interact with nongenetic
factors, including psychological and social influences, to determine sexual
orientation, said Sanders, a psychiatrist.

Still, he said, "If there's one gene that makes a sizable contribution, we
have a pretty good chance" of finding it.

Many gays fear that if gay genes are identified, it could result in
discrimination, prenatal testing and even abortions to eliminate
homosexuals, said Joel Ginsberg of the Gay and Lesbian Medical Association.

However, he added, "If we confirm that sexual orientation is an immutable
characteristic, we are much more likely to get the courts to rule against
discrimination."

There is less research on lesbians, Sanders said, although some studies
suggest that male and female sexual orientation may have different genetic
influences.

His new research is an attempt to duplicate and expand on a study published
in 1993 involving 40 pairs of gay brothers. That hotly debated study,
wrongly touted as locating "the gay gene," found that gay brothers shared
genetic markers in a region on the X chromosome, which men inherit from
their mothers.

That implies that any genes influencing sexual orientation lie somewhere in
that region.

Previous attempts to duplicate those results failed. But Sanders said that
with so many participants, his study has a better chance of finding the
same markers and perhaps others on different chromosomes.

If these markers appear in gay brothers but not their straight brothers or
parents, that would suggest a link to sexual orientation. The study is
designed to find genetic markers, not to explain any genetic role in
behavior.

And Sanders said even if he finds no evidence, that won't mean genetics
play no role; it may simply mean that individual genes have a smaller
effect.

Skeptics include Stanton Jones, a psychology professor and provost at
Wheaton College in Wheaton, Ill. An evangelical Christian, Jones last month
announced results of a study he co-authored that says it's possible for
gays to "convert" - changing their sexual orientation without harm.

Jones said his results suggest biology plays only a minor role in sexual
orientation, and that researchers seeking genetic clues generally have a
pro-gay agenda that will produce biased results.

Sanders disputed that criticism.

"We do not have a predetermined point we are trying to prove," he said. "We
are trying to pry some of nature's secrets loose with respect to a
fundamental human trait."

Jones acknowledged that he's not a neutral observer. His study involved 98
gays "seeking help" from Exodus International, a Christian group that
believes homosexuals can become straight through prayer and counseling.
Exodus International funded Jones' study.

The group's president, Alan Chambers, said he is a former homosexual who
went straight and believes homosexuality is morally wrong.

Even if research ultimately shows that genetics play a bigger role, it
"will never be something that forces people to behave in a certain way,"
Chambers said. "We all have the freedom to choose."

The Cabrera brothers grew up in Mexico in a culture where "being gay was an
embarrassment," especially for their father, said Mauricio, 41, a car
dealership employee from Olathe, Kan.

They had cousins who were gay, but Mauricio said he still felt he had to
hide his sexual orientation and he struggled with his "double life." Julio
said having an older brother who was gay made it easier for him to accept
his sexuality.

Jim Larkin, 54, a gay journalist in Flint, Mich., said the genetics study
is a move in the right direction.

Given the difficulties of being gay in a predominantly straight society,
homosexuality "is not a choice someone would make in life," said Larkin,
who is not a study participant.

He had two brothers who were gay. One died from AIDS; the other committed
suicide. Larkin said he didn't come out until he was 26.

"I fought and I prayed and I went to Mass and I said the rosary," Larkin
said. "I moved away from everybody I knew ... thinking maybe this will
cause the feelings to subside. It doesn't."

Sanders' research: http://www.gaybros.com

Exodus International: http://www.exodus.to