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Human 'cloning' : a discussion paper for the World Medical Association

October 1999

Introduction
The aim of this paper
A key factor in the success of any debate is that the terms used are clearly understood by all participants. Debate about cloning frequently fails on this very basic point. Since the birth of Dolly the sheep ('Viable Offspring Derived from Foetal and Adult Mammalian Cells', Nature 385, 1997; 881 in February 1997), consideration of the issues has been seriously hampered by the use of the term 'cloning' to refer to a wide and diverse range of activities. The primary aim of this paper is to clarify the fundamental differences between the various techniques which have been included under this broad heading. The first part of the paper will focus on the conventional understanding of cloning - those techniques which are intended to bring into existence genetically identical individuals - whether by cell-nuclear replacement or embryo splitting. The second part of the paper will cover other uses of the technology, which have been referred to as cloning but which have fundamentally different aims, objectives and outcomes, such as the development of tissue for transplantation, preimplantation genetic diagnosis and some basic biological research.

Terminology
In addition to the misunderstanding created by using the word cloning in both conventional and unconventional ways, there is also a risk that some of the less controversial areas of research may be judged by popular prejudice rather than careful analysis. The word cloning has strong negative overtones based on its use in the popular fiction of 'Brave New World' and 'The Boys from Brazil' (A 1998 social research study by the Wellcome Trust into public perspectives on human cloning found that a large number of participants expressed their concerns by way of reference to popular cultural imagery such as science fiction films and media stories about the lives of public figures. Wellcome Trust, 'Public Perceptions on Human Cloning'. London; The Wellcome Trust, 1998). This image is so deeply engrained in the public's sub-conscious that the simple use of the word immediately evokes fear and negativity which hinders objective debate about the issues.

Attempts to clarify the terminology have received a mixed response. The consultation document issued jointly by the UK's Human Genetics Advisory Commission and the Human Fertilisation and Embryology Authority (Human Genetics Advisory Commission (HGAC) and Human Fertilisation and Embryology Authority (HFEA). 'Cloning Issues in Reproduction, Science and Medicine: A Consultation Document'. London; HGAC/HFEA, January 1998), distinguished between 'human reproductive cloning' where the intention was to create genetically identical human beings (see Part 2) and 'therapeutic cloning' which included other uses of the techniques for medical or scientific purposes (see Part 3). The choice of the word 'therapeutic', however, was criticised by some people as attempting to influence the outcome of the debate by using a 'positive' term which could be seen as directing respondents towards acceptance of the activities. It was therefore abandoned in the report that followed the consultation. Given these difficulties of terminology, it would seem desirable, if possible, to avoid the term cloning altogether although this is likely to be interpreted as an attempt to sanitise the subject matter in order to manipulate opinion. Instead, this paper restricts the use of the word to its commonly-understood meaning of the deliberate creation of genetically identical individuals - what is often called 'reproductive cloning'.

Common misperceptions
Much of the debate about cloning in the popular media has been based on the mistaken premise that a human clone would be an exact replica of the original person (the nucleus donor). The technique used to create Dolly does not result in the clone and the nucleus donor having exactly the same genetic make-up (see below). But, even if they were genetically identical, the idea that the clone would be a 'copy' or 'replica' of the nucleus donor is based on extreme genetic determinism. The clone and the nucleus donor would not be identical people. Personality, character and behaviour are not determined by genetic factors alone but by a complex interaction of genetic, social, political, historic and environmental factors. Experience of monozygotic twins (which can be considered as naturally occurring clones) is sufficient to illustrate that genetic identity is not the same as personal identity.

Another common misperception is that the clone would be the same age as the nucleus donor so that if the person to be cloned was an adult, the clone would appear as an adult. Although the clone, or clones, would have the same nuclear DNA as the nucleus donor, he or she would begin as an embryo, develop into a fetus , a baby and years later, an adult (Some questions have been raised, however, about whether Dolly's genetic age is the same as her chronological age or whether it is the same as the sheep whose nuclear DNA was used). The time difference between the birth and upbringing of the nucleus donor and those of his or her clones, and the inevitable differences in factors such as womb-environment, mother's diet, social, political and economic circumstances, will undoubtedly increase the differences between the individuals (If more than one clone is produced from an adult or child, the clones will be the same age as each other but will not be the same age as the nucleus donor).