Monday, January 03, 2005

Another Update on Cloning

The latest issue of the New England Journal of Medicine has an article that clarifies some of the science, as well as the ethical issues, regarding human cloning. 
Human Cloning — The Science and Ethics of Nuclear Transplantation
Rudolf Jaenisch, M.D.
Volume 351:2787-2791         December 30, 2004         Number 27

In addition to the moral argument against the use of somatic-cell nuclear transfer for the creation of a child ("reproductive cloning"), there are overwhelming scientific reasons to oppose this practice. In contrast, many believe that the practice of somatic-cell nuclear transfer with the goal of generating an embryonic stem-cell line (sometimes referred to as "therapeutic cloning") is justified, because it holds the promise of yielding new ways of studying and treating a number of diseases. Once isolated from a patient, an embryonic stem cell thus derived would be "customized" to the needs of the patient who had served as the nuclear donor and thus would obviate the need for immunosuppressive treatment as part of a therapeutic application. In addition, because embryonic stem cells can generate most, if not all, types of cells in vitro, a stem cell isolated from a patient with a complex genetic disease could be used to study the pathogenesis of the disease in culture. [...]
Unfortunately, this article was not published on an open-access basis.  I'm not sure why not; often, they provide open access to editorials of public interest.  On the other hand, it is such a technical article, that it might not be very informative to nonscientists.

Dr. Jaenisch discusses, in detail, the reasons that reproductive cloning is not feasible for the reproduction of humans.  He then discussed the distinction between reproductive cloning and therapeutic cloning.  The latter technique, therapeutic cloning, is more accurately called somatic-cell nuclear transfer (SCNT).  In this post,  I review what Dr. Jaenisch has to say on the topic, and use this to illustrate why it is so important to understand some of the science in order to make an informed judgment about the ethics of stem cell technology.  Read the rest at The Rest of the Story