Embryo test for sickle cell starts ethics debate

A genetic test carried out on embryos during in vitro fertilisation (IVF) has been used to prevent two carriers of sickle cell anaemia from passing the disease on to their children. Preimplantation genetic diagnosis (PGD) for sickle cell disease has resulted in its first success - the birth of healthy twin girls to carrier parents, report researchers in last week's Journal of the American Medical Association. Where both parents carry the sickle cell gene, there is a 25 per cent chance of the resulting child being affected by the disorder.

Until now, carriers of sickle cell disease were only offered the chance of prenatal diagnosis and possible termination. In this case, the embryos collected during an IVF cycle were tested for their sickle cell status and only unaffected embryo were transferred back to the woman's womb. PGD is not widely available and is only offered to high-risk couples at select centres.

A statement issued by the Weill Medical College at Cornell University in New York City, where Dr Zev Rosenweks and colleagues carried out PGD for sickle cell disease, notes that the centre offers the test to 'select couples who suffer from genetic disorders...including Tay-Sachs disease, Down syndrome, cystic fibrosis, thalassemia, and Fanconi's anemia.'

However, the report has rekindled the debate over PGD in the US. The powerful anti-abortion lobby are accusing the procedure of being eugenic and equivalent to abortion because it involves 'the destruction of embryonic children' (Pro-Life Infonet).