By Nate Raymond

A U.S. judge has blocked the state of Georgia from enforcing a new Republican-backed law that bars doctors from providing hormone replacement therapy to treat gender dysphoria in transgender children under the age of 18.

U.S. District Judge Sarah Geraghty in Atlanta issued an injunction on Sunday after finding that a group of parents and transgender minors who challenged the law would likely succeed in establishing that the prohibition on hormone replacement therapy violated a provision of the U.S. Constitution.

The ruling marked the latest instance of a federal judge blocking laws banning medical procedures for transgender youth. Republican lawmakers in several states have passed such laws.

Governor Brian Kemp, a Republican, in March signed Georgia's law, which bans certain medical procedures and therapies for minors who experience gender dysphoria, which refers to the psychological distress that some individuals experience because of a mismatch between their biological sex and gender identity. It took effect on July 1.

A group of families and an organization called TransParent sued in federal court, arguing that the prohibition on hormone replacement therapy violated a minor's rights under the Constitution's 14th Amendment to equal protection under the law.

Geraghty, appointed to the bench by Democratic President Joe Biden, agreed, saying the ban amounts to a sex-based classification as it "places a special burden on transgender minors because their gender identity does not match their birth sex."

The judge said that amounts to a form of unconstitutional sex discrimination because a minor's sex at birth determines whether that child can receive a given form of medical treatment.

The state argued that banning hormone therapy was justified by the risk that an individual may later in life regret the physical changes brought on by hormone replacement therapy. But Geraghty said Georgia presented "little" reliable evidence of regret. By contrast, research showed mental health benefits from allowing the treatment of gender dysphoria, the judge said.

"Without an injunction, the middle-school-age plaintiffs will be unable to obtain in Georgia a course of treatment that has been recommended by their health care providers in light of their individual diagnoses and mental health needs," the judge wrote.

A spokesperson for Georgia Attorney General Christopher Carr, a Republican who defending the law, did not respond to a request for comment.

(Reporting by Nate Raymond in Boston, Editing by Will Dunham and Alexia Garamfalvi)