S.C. Code § 44-20-378
A county board of disabilities and special needs established pursuant to Section 44-20-375 must consist of not less than five members. If the board is created within a combination of counties, the number of members representing each county must be proportional to the county's population in relation to the total population of the counties served by the board. However, a county participating in a multicounty board must not have less than two members. The term of the members is four years and until their successors are appointed and qualify. Vacancies for unexpired terms must be filled in the same manner as the original appointments. A member may be removed by the appointing authority for neglect of duty, misconduct, or malfeasance in office after being given a written statement of reasons and an opportunity to be heard.
S.C. Code § 44-20-378