By now, you’ve probably heard about Gavin Grimm, the transgender boy in Virginia whose plea to use the boys’ bathroom has been taken up by the Supreme Court. But I doubt you know about Hazel Juco, a Michigan teen suspended recently for documenting filth in a bathroom for girls.

Juco’s high school disciplined her for posting a photo of brown water coming out of a bathroom tap, a recurring problem in schools nationwide. And in any reasonable world, the abominable condition of school bathrooms would be seen as every bit as shameful as the exclusion of transgendered kids from some of them.

But that’s not the world we live in now. If you suffer because of your “identity,” you get ink and sympathy and lawyers. But if you suffer simply because of where you live and go to school, tough luck.

I support Grimm, a courageous young man who is merely asking to use the bathroom that corresponds to his gender. And I applaud the Obama administration for insisting that Grimm and other transgendered kids receive protection under federal law barring discrimination on the basis of sex.

But I’m also concerned about the thousands of kids who can’t or won’t use a school bathroom, whatever their gender. According to former Georgia teacher and school board member Tom Keating, who has spent years studying the issue, more than one-third of the country’s school bathrooms are dirty, unhealthy or unsafe. Stall doors fall off, soap dispensers break, mirrors crack, and toilets remain clogged for days or even weeks.

So the kids do what you or I would do: They hold it in. That leaves them vulnerable to incontinence and urinary tract infections. And it interferes with learning, too, because it’s hard to focus on history or geometry when all you can think about is how much you have to go.

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Not surprisingly, these problems are most common in our least advantaged schools.

So why do the bathroom travails of transgendered students get so much attention, while the kids who can’t use any bathroom get neglected or virtually ignored? Part of the reason lies in our lurid obsession with transgenderism itself, even among people who are proud of their nonjudgmental bona fides.

But there’s more. Many advocates insist that the transgendered are, to borrow from Lady Gaga, “born that way” — that is, that their gender identity is biologically determined. So the transgendered draw more sympathy than people who live in poverty, who presumably share more responsibility for their fate.

That ignores scientific research on transgenderism, which is only partially rooted in genetic inheritance. And even if you were to grant the premise that transgendered people inherit their condition and poor people earn theirs, surely we shouldn’t hold poor kids responsible for the sins of their fathers and mothers. It should be just as deplorable to deny children access to a bathroom because of economic circumstances as it is to do so because of gender.

But school bathrooms are a pungent reminder of the many ways that our kids get ripped off because of where they were born. The biggest factor in schooling isn’t your gender. It’s your ZIP code.

Jonathan Zimmerman is a professor of history of education at the University of Pennsylvania. He is the author of “Campus Politics: What Everyone Needs to Know.”