S.C. Code § 40-15-20
2012 Act No. 222, Section 15, provides as follows:
"SECTION 15. Notwithstanding any other provision of law to the contrary, any person elected or appointed to serve, or serving, as a member of any board, commission, or committee to represent a congressional district, whose residency is transferred to another district by a change in the composition of the district, may serve, or continue to serve, the term of office for which he was elected or appointed; however, the appointing or electing authority shall appoint or elect an additional member on that board, commission, or committee from the district which loses a resident member on it as a result of the transfer to serve until the term of the transferred member expires. When a vacancy occurs in the district to which a member has been transferred, the vacancy must not be filled until the full term of the transferred member expires."