Miss. Code § 41-37-25
An autopsy may be performed without court order by a qualified physician when authorized by (a) the decedent, during his lifetime, or (b) any of the following persons who have assumed custody of the body for the purpose of burial: a surviving spouse, either parent or any person in loco parentis, a descendant over the age of eighteen (18) years, a guardian, or the next of kin. In the absence of any of the foregoing persons any friend of the deceased who has assumed responsibility for burial, or any other person charged by law with responsibility for burial, may give such consent. If two (2) or more persons have assumed custody of the body of an adult for purposes of burial, the consent of one (1) such person shall be deemed sufficient.
In the case of a minor, however, the consent of either parent shall be deemed sufficient, unless the other parent gives written notice to the physician who is to perform the autopsy of such parent's objection thereto before the beginning of the autopsy. If neither parent has legal custody of the minor, the guardian shall have the right to authorize an autopsy. The fees provided in this chapter for autopsies in criminal investigations shall not be applicable to this section.
No autopsy shall be held under this section over the objection of the surviving spouse, or if there be no surviving spouse, of any surviving parent, or if there be neither a surviving spouse nor parent, then of any surviving child.
If the body has already been buried, consent to disinterment of the body for an autopsy without a court order shall be governed by Section 41-43-59.
Miss. Code § 41-37-25