A lawsuit filed by a transgender teen in Virginia over the right to use the boys’ bathroom at his high school rather than a gender-neutral bathroom similar to the one pictured above could affect school policies across the country. (Toby Talbot/AP)

A transgender teen’s fight to use the boys’ bathroom at his high school in a rural corner of Virginia could shape how schools across the country deal with the question of whether transgender teens have the right to use bathrooms in accordance with their gender identities.

Gavin Grimm, 16, and his attorneys on Wednesday took the teen’s case to the U.S. Court of Appeals for the 4th Circuit, where judges will determine whether banning Gavin, who was born a girl, from the boys’ bathroom constitutes sex discrimination and violates federal law. Gavin sued the Gloucester County School Board in the fall, asking for a preliminary injunction to allow him to use the boys’ bathroom.

Fights over whether transgender students should be allowed to use the bathroom that matches their gender identity have sprouted around the country. But this is the first time a federal appeals court has taken up the question of whether bathroom restrictions for transgender students violate Title IX — the federal law barring discrimination based on gender in schools — and the case is being closely watched by activists on both sides of the issue. Four states and two governors have filed amicus briefs supporting the school board.

“It will likely be a bellwether one way or another that people will look to in the immediate future to look to see where courts are headed,” said Joshua Block, the American Civil Liberties Union attorney arguing Gavin’s case. David Corrigan, who is representing the Gloucester County school board, did not respond to a request for comment.

If the judges rule in Gavin’s favor, it could clear the way for other transgender students to assert their rights to use the bathroom that corresponds with their gender identity and for supporters of transgender students to argue for greater protections in the nation’s schools. If they rule against Gavin, it could give those fighting for bathroom restrictions more ammunition.

Gavin, who was born a female but came out as male when he was 15, said this is an important fight. He said being forced to use a separate, unisex bathroom has exacerbated the anguish of being a transgender teenager. His legal fight, too, has made him the target of “ridicule.”

“I feel humiliated and dysphoric every time I’m forced to use a separate facility,” Gavin said in a conference call Monday.

Those who support the bathroom restrictions have called them “common sense” and have argued that allowing transgender students to use the bathrooms in accordance with their gender identities could frighten other students or violate their privacy.

“I think the ACLU’s attempt to twist Title IX is way beyond the intent of the law,” said Mat Staver, the founder of Liberty Counsel, which is representing a Virginia woman suing a local school district for passing a law protecting LGBT students and staffers from discrimination.

After Gavin came out as male, he began using the boys’ bathroom at Gloucester High. After seven weeks, angry parents raised the issue with the school board. Their complaints prompted the board to pass a policy requiring students to use the bathroom that corresponds with their “biological gender” and requiring transgender students to use separate, unisex facilities.

With the help of the ACLU, Gavin fought the policy in federal court, asking for a preliminary injunction that would allow him to use the boys’ bathroom. The Justice Department backed Gavin’s position. But in October, Judge Robert G. Doumar of the Eastern District of Virginia denied his request. Gavin’s attorney appealed the case to the U.S. Court of Appeals for the 4th Circuit, based in Richmond.

School districts have struggled with whether to allow transgender students to use the bathrooms and locker rooms that correspond with their gender identities, in large part due to concerns about the privacy of other students using those facilities.

The U.S. Education Department, ruling that locker-room restrictions for transgender students constitute sex discrimination, pressed an Illinois school district in December to allow a transgender student to use the girls’ locker room.

In Virginia, a state lawmaker recently proposed a bill that would require schoolchildren and others to use public bathrooms that corresponded to their “anatomical sex” and called for fining those who don’t comply.

Fairfax County, the state’s largest school district, has been taken to court over its decision to enact protections for LGBT staffers and students, although the district has yet to implement a specific policy around bathrooms and locker rooms. Andrea Lafferty, head of the Traditional Values Coalition, and an anonymous student sued the district in December, arguing that the school board acted outside its authority by extending protections to gay and transgender students and staffers. The male student, in a court filing, called the possibility of using a locker room with a transgender student who has female anatomy “terrifying.”

Gail Deady, a legal fellow with the ACLU of Virginia, said if judges rule that bathroom restrictions constitute sex discrimination, it would send a “strong signal” to state courts and state lawmakers that restrictive bathroom policies run afoul of federal law. If judges rule against Gavin, it could lead more school districts to pass restrictive bathroom policies.