In a controversial documentary for the Discovery Channel aired last week, Dr Panayiotis Zavos, a notorious US fertility doctor, claimed to have successfully created and implanted cloned human embryos with the intention of producing live human clones. Scientists and medical ethicists have unanimously condemned him for his actions, both questioning the truth of his claims and denouncing the performance of any such experiments.

Dr Zavos, who heads fertility clinics in the US and Cyprus, his place of birth, announced that he created 14 human embryos, 11 of which he implanted into four women, although none of these resulted in a viable pregnancy. Human cloning is illegal in the UK and many other countries, and the experiments were reportedly carried out in laboratories in a secret location in the Middle East. Dr Zavos has been widely criticised for using a technique that has been deemed too risky and too poorly understood for use in humans, and for neglecting to consider the moral and ethical implications, or the psychological effects on the potential parents and the cloned child.

Cloning experiments have been successful in many different animal species since the much-publicised birth of the first ever cloned mammal, Dolly the sheep. However, cloned embryos often have genetic defects and frequently result in miscarriages, still births or deformed offspring. The reasons for this are not known. Professor Azim Surani, professor of reproduction and fertility at Cambridge University, UK, said: 'This whole affair shows a complete lack of responsibility. If true, Zavos hasÖfailed to observe the universally accepted ban on human cloning, which was agreed because most of the resulting embryos from such animal experiments are abnormal'.

In addition to the creation and implantation of human clones, Dr Zavos has also announced the successful creation of animal-human hybrid embryos where human nuclear DNA was implanted into cow eggs. The resulting embryos would contain more than 99 per cent human DNA but the DNA in the mitochondria, which are the power-houses of cells, would come from the cow eggs. Dr Zavos stated that he had no intention of implanting such embryos, but created them only in order to study the cloning process. Nonetheless, he openly claimed to have created hybrid embryos using the DNA from a ten-year-old girl who died in a car crash and whose parents had expressed an interest in having a new child cloned.

Dr Zavos' scientific integrity has also been called into question, as none of these experiments have been published in a peer-reviewed scientific journal and so no other scientists have examined his methods or results. Professor Robert Winston, emeritus professor of fertility studies at Imperial College London said: 'I do not know of any credible evidence that suggests Dr Zavos can clone a human being. This seems to be yet another one of his claims to get repeated publicity'.

Reproduced from BioNews with permission, a web- and email-based source of news, information and comment on assisted reproduction and human genetics, published by Progress Educational Trust.