The Useful Sibling

Molly Nash was born with the genetic disorder called “Fanconi anaemia,” which leads to a failure to produce bone marrow. Children with this disease normally suffer from severe bleeding and disorders of the immune system. They usually live no more than eight or nine years. The only known effective treatment is a bone marrow transplant from a healthy sibling who is a perfect match. Molly was an only child.

Molly’s parents, Jack and Lisa tried to save Molly’s life in a novel way. They first produced embryos through In Vitro fertilization (IVF). Doctors then used preimplantation genetic diagnosis (PGD) to select a healthy embryo that did not also carry the disease. The first IVF cycle failed, as did the second. Eventually, after four cycles, Mrs. Nash became pregnant and gave birth to a boy, Adam, whose umbilical cord supplied stem cells to replace Molly’s bone marrow. Adam was the fifteenth embryo.

Before this case, PGD was used to let scientists select and implant embryos that did not carry faulty genes. In the United Kingdom, PGD had been used for ten years by five different clinics, resulting in the birth of about twenty healthy babies who would otherwise have been at risk of a variety of serious genetic diseases. According to James Yeandel, of the Human Fertilisation and Embryology Authority, “Use of PGD has been approved for a number of serious genetic diseases on a named disorder basis. It cannot be used for any social, physical, or psychological reasons.”

Dr. Vivienne Nathanson, the Head of ethics and policy for the British Medical Association, pointed out that the techniques used to save Molly’s life would not be allowed under British law, because the child might be seen simply as a “medical product.” She said, “You obviously have sympathy with the family but we have to have concern about the second child. We would have very serious concerns that he is a commodity rather than a person.”