D.C. charter board staff are recommending that Basis Public Charter School should not be allowed to add 35 seats next year because a large number of students are leaving in the middle of the school year.

The Ward 2 school, which opened this year, is currently allowed to enroll up to 468 students. But at the beginning of October, the number of students at the middle school was 443, and a more recent count shows 417 students enrolled, according to documents the school provided to the charter board.

A representative of Basis did not return requests for comment.

Basis also has a small number of special needs students compared with other public schools in the city, said charter board Deputy Director Naomi Rubin DeVeaux. Only 5 percent of the student body have special needs, compared with an average of 12 to 14 percent elsewhere.

That and the midyear drop represent "some troubling early data" for the school, which is in its first year, the charter board staff explained in a memo prepared for Monday's board meeting.

The school is already slated to add 43 students next year, including 26 in a new ninth grade, which will bring the enrollment cap to 511. The staff has recommended denying the school's request to increase that cap to 546.

Basis was one of 11 charter schools that asked to increase enrollment in the fall.

- Rachel Baye