Ethical and Policy Issues in Human Embryo Twinning

Abstract

In 1993, investigators from George Washington University (GWU) Medical Center separated the cells of 17 human embryos and produced 48 embryos, an average of three embryos for each original. The method, variously called twinning, cloning, embryo splitting, and blastomere separation, demonstrated that human embryos could be split to create genetically identical entities during conception. When publicized, however, the experiment brought to mind a different view of cloning repeated since the beginning of the new reproductive technologies. In the early 1970s, when research onin vitrofertilization (IVF) was in its infancy, commentators worried that cloning–defined as the duplication of persons–would be next, leading to a scenario of “boys genetically exactly like the father, girls like the mother, or individuals like some true or false hero of art, science, or sports, or like some demagogue or some saint.”

Ooplasmic and nuclear transfer to prevent mitochondrial DNA disorders: conceptual and normative issues

“…As there will be a substantial time gap between the start of both lives, the clone has to live in the shadow of its 'original' (Holm, 1998;Buchanan et al, 2000). This argument, however, does not hold true for embryo cloning, at least insofar as twins thus conceived have a simultaneous start in life; this is not different from twins in the natural course of events (Bonnicksen, 1995;De Wert, 2000). Although they start their lives as genetically identical twins, they also begin their biography at the same time.…”

Das Klonen von Menschen Eine alte Debatte - aber immer noch in den Kinderschuhen

“…Sie erhofften sich daraus einen Nutzen für die Erforschung von Krebs in verschiedenen Geweben (siehe [3]). 1961 gelang es dem Oxforder Zoologen Gurdon, mittels der gleichen Technik ein Gelege von Kröten zu kreieren, deren genetische Eigenschafen identisch waren (siehe [11]) 2 Erstmals äußerten Ramsey und Fletcher ihre Kommentare hinsichtlich des Klonens von Menschen auf einer 1968 vom Institute of Religion des Texas Medical Center durchgeführten Konferenz. Ihre Auffassungen finden sich in [25] und [9] Times, Forschern an der George-Washington-Universitätsklinik in Washington D.C. sei die Klonierung von menschlichen, jedoch von mehr als einer Samenzelle befruchteten und dadurch nicht überlebensfähigen Embryonen gelungen 3 .…”

Ethics at the interface of reproductive medicine and genetic technology : the case of mitochondrial disorders

“…As there will be a substantial time gap between the start of both lives, the clone has to live in the shadow of its 'original' Buchanan et al, 2000). This argument, however, does not hold true for embryo cloning, at least insofar as twins thus conceived have a simultaneous start in life; this is not different from twins in the natural course of events (Bonnicksen, 1995;de Wert, 2000). Although they start their lives as genetically identical twins, they also begin their biography at the same time.…”

“…Being alone as a clone, the child will not have to suffer from living in the shadow of a genetically identical individual. The second exception is when the twins, conceived by means of REC, are born simultaneously; this would not be different from identical twins in the natural course of events (which can be considered as naturally occurring clones) (Bonnicksen, 1995;British Medical Association, 1999;De Wert, 2000). Although they start their lives as genetically identical twins, and although they may share many characteristics, they also begin their biography at the same time.…”