If a sample of an individual's genetic material that could identify another individual as the decedent's heir is not available for purposes of conducting genetic testing under this subchapter, the court, on a finding of good cause and that the need for genetic testing outweighs the legitimate interests of the individual to be tested, may order any of the following individuals to submit a sample of genetic material for the testing under circumstances the court considers just:
(1) a parent, sibling, or child of the individual whose genetic material is not available; or
(2) any other relative of that individual, as necessary to conduct the testing.