A high-profile doctor and transgender care advocate appearing as a Democrat witness before a U.S. congressional committee was unable to cite a single study for the benefits of transgender surgeries.

U.S. Rep. Dan Crenshaw (R-TX) challenged her to name one.

Dr. Meredithe McNamara, professor at Yale School of Medicine, appeared last week before the House Committee on Energy and Commerce. She was scheduled to speak as an expert on what she considers government interference into the standard of care for transgender youth.

In her prepared testimony, McNamara said there is “substantial medical research and evidence” for gender-affirming care (GAC) being the standard.

“Gender-affirming care is the only evidence-based treatment for gender dysphoria, a condition that reflects a discordance between one’s gender identity and sex assigned at birth … The scientific evidence shows that GAC is lifesaving care that improves mental health and physical well-being in those experiencing gender dysphoria,” McNamara said.

McNamara then explained how a GAC ban would cause harm.

“When evidence-based care of gender dysphoria is interrupted or restricted, suicide, depression, anxiety, disordered eating, and poor quality of life follow.”

But when Crenshaw requested McNamara identify the evidence, she failed to cite any.

“It’s good to look at systematic reviews, right? Crenshaw asked, adding, “That’s the gold standard of evidence when you’re trying to understand whether something works or it doesn’t.

“The British Journal of Medicine looked at 61 systematic reviews with the conclusion that, quote, ‘There is great uncertainty about the effects of puberty blockers, cross-sex hormones and surgeries in young people.’ The Journal of the Endocrine Society came up with the same conclusion, even the American Academy of Pediatrics. They all cite the lack of evidence,” he continued.

The congressman asked: “Which journal says something different?  We should have that debate. Tell me a journal that has done systematic reviews that cites different evidence, that cites strong evidence of benefits for these therapies.”

In her response, McNamara referred back to the standard of care, saying, “The standards of care were developed based on extensive …”

Crenshaw cut her off there to ask for one study.

“You’re not telling me any study, don’t say ‘standards of care.’ Tell me one.”

Crenshaw’s time expired without McNamara giving a study example as he requested.

Crenshaw has taken a leading role in efforts to block federal money from being sent to hospitals that perform transgender treatments or procedures on minors.

The Children’s Hospital GME Support Reauthorization Act funds pediatric residencies nationwide.

Crenshaw has introduced legislation that would prevent taxpayer funding of hospitals that offer “gender-affirming care” to minors.