As in most states, Texas family law prohibits same-sex marriages. These two women can legally get married, though, because one of them was born a man.

An opinion last year by the state 4th Court of Appeals in San Antonio said chromosomes -- not sex-change operations or outward gender characteristics -- determine a person's gender.

In that case, the court invalidated the marriage of a couple because it said the woman, who had been born a man but had undergone a sex-change operation before the marriage, was still legally a man and therefore not legally married.

That ruling worked in the favor of Jessica Wicks, 53, and Robin Wicks, 44. They're thought to be the first couple living as the same gender to be granted a marriage license in Texas.

It's not clear what impact the case might have on gay rights issues in Texas, but many say it will likely call attention to same-sex marriages and thorny questions about who determines a person's gender -- and how.

"It points out, partially, how ridiculous all of this is. Marriage is a private matter," said Dianne Hardy-Garcia, executive director of the Lesbian/Gay Rights Lobby of Texas. "I don't think the state has any business defining who should be able to get married between consenting adults."

Rep. Arlene Wohlgemuth, R-Burleson, the president of the Texas Conservative Coalition, said although the case is unusual, the group does not oppose the Wicks' wedding even though both partners live as women.

"We don't object to a marriage license being issued since we do favor a marriage between a man and woman and this fits the legal definition of gender," Wohlgemuth said. "They are legally a man and a woman. What they do once they are married is up to them."

But other issues complicate things, said Jack Sampson, a University of Texas law professor. Not everyone is born with a set of chromosomes, XX or XY, that clearly defines their gender. Hermaphrodites and other cases of confused genetics could pose problems, he said.

In its opinion, the 4th Court of Appeals said the Legislature is a better venue for deciding gender. And some advocates for transsexuals say they'll ask lawmakers to do that next year.

Phyllis Randolph Frye, an attorney for the Wicks, said yesterday she'll encourage other transsexuals to travel to San Antonio and get married. She hopes such a groundswell would give traditional gay couples ammunition to question why they can't be wed, too.

Frye also represents Christie Lee Littleton, who is fighting the 4th Court of Appeals' ruling that came in her wrongful-death lawsuit against a doctor who treated her husband, who died in 1996. The court threw out the suit and Littleton's marriage because Littleton was a male by birth.

The Texas Supreme Court has twice refused to hear the case, which is pending before the U.S. Supreme Court.

The Wicks met about three years ago. Jessica was born Grady Roland Wicks and has an "M" on her birth certificate. About a year ago she took steps to legally become a woman, Frye said. News reports have said Jessica has had a sex-change operation, but she and her attorney refuse to confirm that. They say it is irrelevant because the 4th Court of Appeals defines gender by chromosomes, not anatomy.

A few weeks ago, Robin changed her last name to Wicks. The couple tried to get a marriage license in Houston but were refused when the county clerk said Jessica was a woman. But Bexar County is one of 32 counties where transsexual couples could argue that the 4th Court's ruling applies because the court covers those counties.

Yesterday, the Wicks clutched their newly acquired marriage license and the office's standard lavender "newlywed kit."

"We know we love each other, and in a real sense we're already married in our heart," Jessica Wicks said. "But there's something about the piece of paper that says this is the way it should be."

Only Vermont, in response to a state supreme court ruling, has legalized a sort of parallel marriage system for same-sex couples.