AUSTIN, Texas — Texas Attorney General Ken Paxton sued a Dallas doctor on Thursday, accusing her of providing gender transition treatments to nearly two dozen minors, violating a 2023 state law.

The lawsuit alleges that Dr. May Lau, a physician at the University of Texas Southwestern Medical Center, "illegally provided high-dose cross-sex hormones to twenty-one minor patients for the direct purpose of 'transitioning' the child’s biological sex," according to a news release from Paxton’s office. The lawsuit marks the first enforcement action against a physician under state law.

Texas is seeking more than $1 million in monetary relief and is asking the court for temporary and permanent injunctions against the doctor's conduct in the lawsuit, among dozens of complaints Paxton's office has filed on hot-button issues in the months leading up to the 2024 presidential election.

Affirmed by the Texas Supreme Court in June, Senate Bill 14 prohibits gender modification surgeries for minors as well as the prescription of "puberty blockers," or medications meant to affect the developments that occur during puberty. The state law stipulates that physicians who violate SB 14 can be stripped of their medical licenses; hospitals can be denied the use of public funds for violations.

Despite the fact most major medical groups support youth access to gender-affirming care, there has been an increasing number of conservative states taking steps to limit access in recent years. As of August, 26 states — including Texas — have passed partial or total bans on gender-affirming care, according to LGBTQ advocacy group Human Rights Campaign.

Earlier this year, a Florida judge blocked the state's ban on transgender health care for children and restrictions for transgender adults, ruling it unconstitutional. In June, the U.S. Supreme Court said it will hear the Biden administration's challenge to a similar law in Tennessee.

These restrictions are part of a wave of anti-LGBTQ laws that have been introduced in statehouses across the country. The American Civil Liberties Union has tracked at least 530 anti-LGBTQ bills that were introduced during the 2024 legislative session.

LGBTQ veterans:Hundreds given honorable discharges after Pentagon 'don't ask, don't tell' review

Paxton accuses doctor of engaging in 'deceptive trade practices'

According to the lawsuit, which does not include records or exhibits, Lau prescribed testosterone to several teenage biological females days before the ban took effect on Sept. 1, 2023, and instructed them to fill the prescriptions after Sept. 1.

In one case, the lawsuit alleges the doctor wrote a new prescription in October. Paxton also alleges in the suit that patients were able to refill the prescriptions several times.

While Lau identifies some of the patients as male, Paxton alleges that "upon information and belief, all of these patients are biological females and Lau is prescribing to them for the purposes of transitioning their biological sex or affirming their belief that their gender identity is inconsistent with their biological sex."

There are exceptions in the ban for intersex children's medical care and minors experiencing early onset puberty or other hormonal disorders, but it's unclear whether those apply to Lau's patients.

Paxton's office also alleges Lau broke a law against "deceptive trade practices" by using false diagnoses to cover up gender-transition treatments, though it only cites one example. In that case, Lau "falsely" billed a patient for treatment of an endocrine disorder while another hospital "correctly" diagnosed the patient with gender dysphoria, according to the filing.

Lau's employer, UT Southwestern, did not immediately respond to an American-Statesman, part of the USA TODAY Network, request for comment.

Lau, an adolescent medicine specialist, also has hospital privileges at Children's Health Medical Center in Dallas and Plano, Texas. The organization denied allegations of wrongdoing.

"Our top priority is the health and well-being of our patients," a spokesperson for Children's Health wrote in a statement. "Children’s Health follows and adheres to all state health care laws."

Though Paxton is not a prosecutor, a provision in SB 14 allows his office to enforce the law by seeking to "restrain or enjoin the person from committing, continuing to commit, or repeating the violation" through civil action.

"Doctors who continue to provide these harmful 'gender transition’ drugs and treatments will be prosecuted to the full extent of the law," Paxton said in the news release Thursday.

In the release, Paxton's office wrote that "evidence obtained by the Office of the Attorney General" revealed the alleged misconduct but did not elaborate further. The attorney general did not respond to the Statesman's questions about the providence and nature of the evidence.

'Doctors should not have to fear being targeted by the government'

Several major medical associations — including the American Academy of Pediatrics, the American Medical Association, and the American Psychiatric Association — support providing developmentally appropriate and individualized gender-affirming medical care for transgender youth.

However, the American Academy of Pediatrics, as well as several national health agencies in Europe, have called for more research on the long-term effects of treatments such as hormone therapy, citing a lack of evidence on their benefits.

The ACLU condemned Paxton's latest suit in a statement Thursday, though the group declined to address specifics of the case.

"This is the predictable and terrifying result we challenged SB 14 to prevent," Harper Seldin, staff attorney for the ACLU's LGBTQ & HIV project, said in an email to the Statesman. "Doctors should not have to fear being targeted by the government when using their best medical judgment and politicians like Ken Paxton should not be putting themselves between families and their doctors.”

The demands are part of a yearslong effort by Paxton, Gov. Greg Abbott, and the state GOP to eliminate transgender health care for minors in Texas. They characterize such health care as dangerous, noting some treatments can result in permanent fertility loss. Transgender health care is legal for adults in Texas.

Democrats have argued that the ban infringes on parents' rights and denies accepted medical care, with some reading letters from trans kids and parents at Abbott's signing of the bill in May 2023. 

Contributing: Thao Nguyen and Maureen Groppe, USA TODAY