Section 26.26A.350 - Genetic testing-Identical siblings(1) If the court finds there is reason to believe that an alleged genetic parent has an identical sibling and evidence that the sibling may be a genetic parent of the child, the court may order genetic testing of the sibling.(2) If more than one sibling is identified under RCW 26.26A.325 as a genetic parent of the child, the court may rely on nongenetic evidence to adjudicate which sibling is a genetic parent of the child.