Story highlights Dana Zzyym is challenging the State Department, claiming discrimination

Zzyym wants a passport that allows "X" for gender

The State Department says it did not violate the plaintiff's constitutional rights

(CNN) A Colorado Navy veteran who identifies as neither male nor female has taken the State Department to court for refusing to administer a gender-neutral passport.

U.S. District Judge R. Brooke Jackson heard arguments in the lawsuit this week, according to a clerk of the court. No ruling has been issued.

Dana Zzyym, 58, was born with ambiguous sex characteristics and identifies as intersex, according to Lambda Legal, which is handling the case. Zzyym uses the gender-neutral pronouns "they" and "them" and wants a passport that has an "X" for gender alongside "male" and "female."

The State Department, which oversees the passport program, sent a statement to CNN this week explaining that its policy, "like other federal, state and local government agencies, requires the use of binary (M or F) sex identifiers."

The current rules put Zzyym in a catch-22, said Paul Castillo, an attorney at Lambda Legal who is on Zzyym's legal team.

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