WASHINGTON — The principal of West Potomac High School in Fairfax County has resigned.

Fairfax County Public Schools spokesman John Torre said that Alex Case’s resignation was effective Friday. Torre would not comment on the reason for Case’s departure.

Before his resignation, Case had been on leave from his job for a time.

In a letter sent to parents on Friday, Case said his decision to step down was not easy to make, but that he is excited to pursue new opportunities to serve the community while dedicating more time to his family.

In a note sent along with Case’s letter, Assistant Superintendent Terry Dade said school officials will share more information about the search for a new principal in the weeks ahead.

Dale Rumberger took over as interim principal last week.

Before leading the school, near Alexandria, Case served as a teacher and assistant principal.

“I believe the time is right to allow others to lead the work we have started and have great confidence in the leadership team in place at West Potomac,” Case said in the letter.