(a) A person commits the offense of incest when such person engages in sexual intercourse or sodomy, as such term is defined in Code Section 16-6-2, with a person whom he or she knows he or she is related to either by blood or by marriage as follows:
(1) Father and child or stepchild;
(2) Mother and child or stepchild;
(3) Siblings of the whole blood or of the half blood;
(4) Grandparent and grandchild of the whole blood or of the half blood;
(5) Aunt and niece or nephew of the whole blood or of the half blood; or
(6) Uncle and niece or nephew of the whole blood or of the half blood.
(b) A person convicted of the offense of incest shall be punished by imprisonment for not less than ten nor more than 30 years; provided, however, that any person convicted of the offense of incest under this subsection with a child under the age of 14 years shall be punished by imprisonment for not less than 25 nor more than 50 years. Any person convicted under this Code section of the offense of incest shall, in addition, be subject to the sentencing and punishment provisions of Code Section 17-10-6.2.