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:
Tex. Estates § 204.054