The Missouri Supreme Court is expected to decide within months whether state law prohibits discrimination based on sexual orientation or gender identity. But the American Civil Liberties Union alleges in a lawsuit that the Missouri Commission on Human Rights has determined that LGBTQ people are not protected.

The lawsuit, filed this week in Cole County Circuit Court, challenges the commission’s dismissal of a case brought by a transgender man who claimed his employer treated him differently because he didn’t conform to stereotypes of masculinity.

“The argument is not new," ACLU of Missouri Legal Director Tony Rothert told KCUR. "As an employer, when you're discriminating against someone because they are not acting or appearing as you think a man or a woman should, that is discriminating against someone because of sex. And that should be unlawful under Missouri's existing law."

According to the ACLU’s lawsuit, the commission said last month that it didn’t have jurisdiction “because sexual orientation is not protected by the Missouri Human Rights Act.”

Adam Pulley, a spokesman for the Labor Department, which oversees the commission, said the agency doesn’t comment on pending litigation.

Sexual orientation is not spelled out in Missouri’s anti-discrimination laws, and the state’s high court currently is considering two cases that will have far-reaching implications for how the Missouri Human Rights Act is applied.

One case involves a gay man, Harold Lampley, who claimed he was harassed by his employer because he didn’t conform to stereotypical masculine behavior. The other involves a transgender teenager who sued the Blue Springs R-IV School District for barring him from using the boys’ bathroom.

Both cases were thrown out in court. Lampley appealed to the Missouri Court of Appeals, which ruled in October that state law prohibits employment discrimination against a person who doesn’t conform to gender stereotypes. Three months earlier, the same court ruled against the transgender teenager, saying the state’s Human Rights Act does not prohibit discrimination based on gender identity.

The split led the state Supreme Court to review the cases. It heard arguments in April and is expected to rule in the coming months.

The ACLU has urged the high court to look to federal cases that have recognized sex discrimination based on sexual orientation. The commission, on the other hand, has argued that Missouri courts have interpreted the law as prohibiting discrimination on the basis of sex, not sexual orientation.

In the lawsuit filed by the ACLU this week, Chris Lawson says he was employed at the Dollar General store in Fulton for about a month and a half in 2015 before he quit. His complaint to the commission alleged Dollar General violated his rights under the Missouri Human Rights Act because it didn’t let him use the men’s restroom and because the human resources department had been told not to use male or female pronouns when referring to him.

State Rep. Greg Razer, D-Kansas City, told KCUR that he thought the commission’s rulings in transgender cases "is looking at the letter of the law, and we need to fix the law so that they can do their job."

Razer has tried to add sexual orientation to Missouri's anti-discrimination laws; in this year’s session, the bill passed in committee but was never debated on the floor.

"There are obviously people in Missouri who are losing their jobs because they're LGBT, and that shouldn't be the kind of state any of us want to be living in," Razer said.

Razer added that he’ll reintroduce his bill in the General Assembly’s 2019 session.

KCUR reporter/newscaster Lisa Rodriguez contributed to this report.

Dan Margolies is a senior reporter and editor at KCUR. You can reach him on Twitter @DanMargolies