S.C. Code § 63-9-1120
An adult person may be adopted by another adult person with the consent of the person to be adopted or his guardian and with the consent of the spouse, if any, of a sole adoptive parent, filed in writing with the court. The provisions of Section 62-2-109 and Sections 63-9-30 through 63-9-760, excluding Section 63-9-740, do not apply to the adoption of an adult person. A petition for the adoption must be filed with the family court in the county where the adoptive parents reside. After a hearing on the petition and after those investigations as the court considers advisable, if the court finds that it is in the best interests of the persons involved, a decree of adoption may be entered which has the legal consequences stated in Section 62-2-109.
S.C. Code § 63-9-1120