savior sibling
... that a savior sibling has undergone preimplantation genetic diagnosis (PGD) in order to serve as a stem cell donor to a diseased sibling?
... that a <b id="mwAl4"><a href="./Savior_sibling" id="mwAl8" rel="mw:WikiLink" title="Savior sibling">savior sibling</a></b> has undergone <a href="./Preimplantation_genetic_diagnosis" id="mwAmA" rel="mw:WikiLink" title="Preimplantation genetic diagnosis">preimplantation genetic diagnosis</a> (PGD) in order to serve as a stem cell donor to a diseased sibling?