Dean Hamer

When I got into work this morning there was a letter and a memo on my desk. The letter was from a “freelance writer with a specialty in contemporary social issues” who wanted to know more about the “gay gene” research that my laboratory became widely known for in 1993. I had never heard of the letter writer, but a few minutes on the Web revealed that he worked for the Family Research Council, an organization that “reaffirms and promotes the traditional family unit.”

I haven’t always gotten letters like this. In fact, I spent most of my 30-year career in genetics working on typically ivory-tower topics like the regulation of yeast metallothionein gene transcription by transition metal ions. Why did I switch from such a respectable field to one as controversial as human sexuality?

As is so often the case in science, the answer is a mixture of curiosity, compassion, and coincidence. Our research on sexual orientation really started as much by accident as by plan. As part of a project to study whether genes play a role in Kaposi’s sarcoma, an unusual form of cancer that was striking down gay men with AIDS in disproportionate numbers, my laboratory began to collect families with multiple homosexuals. I realized that this would provide a unique resource to study the genetics not only of the cancer but also of sexual orientation. It was a fascinating question just waiting to be tackled with the tools of modern biology, but no molecular biologist had ever worked on it before.

In my case the idea fell on fertile ground. The notion of a genetic component to homosexuality was hardly new to me. My mother came out as a lesbian when she was 50, my sister when she was 26. And I knew that many of my gay friends had gay relatives including uncles, aunts, and cousins as well as brothers and sisters.

Our research revealed an interesting pattern in the families of the gay men we were studying: Most of the homosexual relatives were on the mother’s side of the family. This suggested that we look at the X chromosome, which is transmitted to males only from their mothers. A DNA linkage experiment demonstrated that there was indeed one particular region of the sex chromosome, called Xq28, that was shared at elevated levels by gay brothers but not their heterosexual siblings.

This was the first molecular evidence for a “gay gene.” Two subsequent studies, including one by a completely independent research team, confirmed the finding in different populations. Although a fourth study, in Canada, failed to replicate the linkage, a meta-analysis of all the data confirmed a significant effect of the Xq28 region in at least some families.

Nevertheless, the letter writer stated that his “personal research” had “not uncovered any information that unequivocally ties sexual orientation to genetics.” I thought of tossing the letter in the wastebasket, but the accompanying memo from my boss requested a response.

So I wrote one, explaining why sexual orientation is important to both basic science and public health and how the NIH tries to include everybody in its research. (It wasn’t too long ago that women and minorities were routinely excluded from protocols.) But what I really wanted to do was to take the letter writer by the collar and scream in his ear, “Don’t you realize that the real danger is in not studying human sexuality?”

Think about it. When AIDS began killing gay men in the United States in the late 1970s, the first thing the epidemiologists needed to know was the incidence of male homosexuality in our country. But there wasn’t any research on that topic.

When it became clear that the disease was sexually transmitted, the next question concerned the sexual practices of gay men. But there wasn’t any research on that topic.

When the main routes of transmission were identified, it became important to know the best way to urge people to have safe sex. But—you guessed it—there wasn’t any research on that topic.

All those “sorry no researches” led to thousands of unnecessary deaths. Some of them were my friends—my close friends. I guess that’s why I believe that ignorance of human sexuality is not bliss. Ignorance is death.

Reminder: Reschedule training session for tomorrow.