A transgender rights supporter outside the U.S. Supreme Court earlier this month as it was hearing arguments in a case on transgender health rights. Kevin Dietsch/Getty Images

A UCLA student is suing doctors and several California health-care providers alleging that she was wrongly diagnosed with gender dysphoria and then "fast-tracked" for transition treatment that led to a double mastectomy at 14, according to a report.

Kaya Clementine Breen, 20, who said she experienced sexual abuse as a young child, said in her lawsuit that she "began struggling with the thought of developing into a woman and began to believe that life would be easier if she were a boy" when she was 11, NBC News reported.

When she confided her thoughts to school officials, a counselor told her "that she was transgender and called her parents to tell them the same."

Breen, who said she was also suffering anxiety, depression and undiagnosed post-traumatic stress disorder, was then taken to the Center for Transyouth Health and Development at Children's Hospital in Los Angeles.

The then-12-year-old Breen was diagnosed with gender dysphoria at the facility and began to receive transition-related care.

She was "fast-tracked onto the conveyor belt of irreversibly damaging" transgender medical procedures that included puberty-suppressing medication, cross-sex hormones and a double mastectomy at 14, the suit says.

All the while, "her mental health progressively declined" following these treatments, the suit says.

"In retrospect, I wish that somebody had suggested real, genuine therapy first, instead of gender-specific therapy, because really the only therapy that I received until much later was specifically focused on gender dysphoria, and didn't connect my gender dysphoria to anything else," Breen told NBC News in an interview.

A spokesperson for the Center for Transyouth Health and Development at Children's Hospital Los Angeles told NBC News that it has "provided high quality, age-appropriate, medically necessary care for more than 30 years."

The spokesperson said the facility doesn't comment on "specific patients and/or their treatment."

Breen said she doesn't believe the health providers "intentionally acted in poor faith," but accused them of being dismissive of her mental health issues.

She hopes to get "some semblance of justice or change" from her lawsuit.

Mostly, she wants to "help dismantle the rumor that no one is ever fast-tracked into gender treatments."