S.C. Code § 59-117-30
In case a vacancy should occur in the board among the members elected by the General Assembly, the Governor may fill it by appointment until the next session of the General Assembly. Any vacancy occurring in the office of the member appointed by the Governor shall be filled for the remainder of the unexpired term by appointment in the same manner of original appointment. Each member of the board shall draw such per diem and expenses as from time to time may be allowed boards, commissions, and committees.
Elections to fill vacancies which are caused by the death, resignation, or removal of an elective trustee may be held earlier than the first day of April of the year in which the unexpired term terminates, but the term of the person elected to fill the vacancy expires on the last day of June of the year in which the term of the former member would have expired.
S.C. Code § 59-117-30