FOUNTAIN, Colo. (AP) - At first, Jeremy and Kathryn Mathis didn't think much of their son's behavior. Coy took his sister's pink blanket, and shunned the car they gave him for Christmas.
Then, Coy told them he only wanted to wear girls' clothes. At school, he became upset when his teacher insisted he line up with the boys. All the while, he was becoming depressed and withdrawn, telling his parents at one point he wanted to get "fixed" by doctors.
When the Mathises were told he had gender identity disorder - a condition in which someone identifies as the opposite gender - they decided to help Coy live as a girl. And suddenly, he came out of his shell.
Coy Mathis, left, plays with his sister, Auri, 2, at their home in Fountain, Colo., Monday.
"We could force her to be somebody she wasn't, but it would end up being more damaging to her emotionally and to us because we would lose the relationship with her," Kathryn Mathis said. "She was discussing things like surgery and things like that before and she's not now, so obviously we've done something positive."
Now, the family is locked in a legal battle with the school district in Fountain, a town 82 miles south of Denver, over where Coy, 6, should go to use the bathroom - the girls' or, as school officials suggest, one in the teachers' lounge or another in the nurse's office. The parents say using anything other than the girls' bathroom could stigmatize the child, and open him up to bullying.
Fountain-Fort Carson School District 8 declined to comment, citing a complaint filed on behalf of the Mathises with the Colorado Office of Civil Rights that alleges a violation of the state's anti-discrimination law. School officials, however, sent a letter to the family, explaining their decision to prevent Coy from using the girls' bathroom at Eagleside Elementary, where he is a first-grader.
"I'm certain you can appreciate that as Coy grows older and his male genitals develop along with the rest of his body, at least some parents and students are likely to become uncomfortable with his continued use of the girls' restroom," the letter read.
School districts in many states, including Colorado, have enacted policies that allow transgender students to use the bathroom of the gender with which they identify. Sixteen states, including Colorado, have anti-discrimination laws that include protections for transgender people.
Legal battles such as the one the Mathises are facing are rare, said Michael Silverman of the New York-based Transgender Legal Defense & Education Fund who is representing the Mathises. He sees about a dozen cases each year. Silverman refers most cases to social workers who work with districts to work out a solution to a well-recognized medical condition.
Psychologists don't know what causes the condition, but it was added to the American Psychiatric Association's diagnostic manual in 1980 - some three decades after the psychological concept of gender began to be developed.
There's no consensus on how to treat it in somebody Coy's age because of a lack of data on the disorder in prepubescent children.
Coy is a triplet, with a brother, Max, and a sister, Lily. At 5 months old, Coy was already expressing a preference for items associated with girls, the Mathises recalled. A friend gave them baby blankets, and Coy took a pink blanket meant for Lily. The Mathises didn't think too much of it.
They bought Coy toys normally associated with boys, but he showed little interest. While Max was excited when Coy opened his Christmas present in 2009 to find a toy car from the Disney movie "Cars," Coy simply set it down and walked away.
As Coy got older, he found and wore his older sister's bathing suit, which had fringe that made it look like a tutu.
Still they pressed on in raising a boy, encouraging Coy to wear boy clothes and bought shirts that had pictures of sports, monsters and dinosaurs on them. He showed little interest, and refused to leave the house if forced to wear boy's clothes.
It didn't bother his father, an ex-Marine, that Coy liked to wear pink bows and dress up in girls clothes. That is, until Coy insisted on leaving the house with them on.
"She would see the stereotypical outfits laid out and then get this look of defeat and then would go, 'I'd just rather stay home,'" his mother said. "It wasn't about the pink. It was about people knowing she was a girl."
When Coy asked to be taken to the doctor to be "fixed," they took him to a psychologist who diagnosed her.
Coy started kindergarten in August 2011 but once the Mathises learned that Coy's behavior wasn't a phase, they allowed him to wear dresses and identify himself as a girl in the middle of the school year.