Imposing a ban on research using human-animal chimera or hybrid embryos would be “unnecessarily prohibitive” and would undermine both “the UK’s leading position in stem cell research and the international reputation of science in the UK," a report by the House of Commons Science and Technology Committee has concluded.

While recognising the need for revised legislation to reflect advances in science and medicine since the passage of the Human Fertilisation and Embryology Act 1990, the committee felt that research using some forms of human-animal chimera or hybrid embryos – or, more specifically, “cytoplasmic hybrid embryos," as they are termed in the report – should be allowed to proceed straight away under licence. “We recommend that the Government propose draft legislation which is immediately permissive, through regulation, to those areas of research it deems acceptable,” it declared.

In January, the Science and Technology Committee launched an inquiry into the government’s White Paper on overhauling the Human Fertilisation and Embryology Act and its potential impact on stem cell research in the UK. A draft Human Tissues and Embryology Bill is scheduled for introduction in May 2007. The White paper proposed clarifying the extent to which existing law applied to hybrid embryos. But it also sought a ban on their creation, while leaving the door open for future regulation that might allow the practice under licence.

This put a question mark over licence applications from King’s College London and Newcastle University to pursue stem cell research using hybrid embryos created by implanting human DNA into animal eggs. In the event, the Human Fertilisation and Embryology Authority (HFEA) decided not to rule on the applications until there had been a “full and proper public debate” on the issue. This was despite concluding that, under current legislation, hybrid embryo research was not only viable but “would potentially fall within the remit of the HFEA to regulate and licence”.

Criticisms of the HFEA

The Science and Technology Committee criticised the HFEA for deferring judgment on the licence applications, saying it was the role of the regulator “to make judgement in areas considered within the spirit of the Human Fertilisation and Embryology Act, and we find delay of assessment of these applications by HFEA inappropriate once the Authority had established that such research is within its remit”. It also criticised the government for not setting out clearly the areas of research that would fall under its proposed legislation.

In general, all forms of human-animal chimera or hybrid embryos should be permitted for research purposes, as long as the practice is appropriately regulated, the committee found. However, it maintained the position of the previous Science and Technology Select Committee that developing hybrids past the 14-day stage in vitro should be prohibited, unless it were proved necessary. Moreover, a ban should be imposed on implanting human-animal chimera or hybrid embryos in women, the committee said.

It also called on the government to ensure through education and dialogue that the public understood the need for, and benefits of, research using hybrid embryos, particularly in view of the “sincere ethical and moral concerns” around the practice.

Scientists and the biotechnology industry have warned that the UK could lose its lead in stem cell research if the government’s proposed ban on hybrid embryos is not overturned. They argue that hybrid embryos are a less cumbersome and more efficient means of harvesting stem cells, as well as addressing the current shortage of human eggs available for research. Liberal Democrat MP Dr Evan Harris, who sits on the Commons Science and Technology Committee, has been a vocal and active supporter of these arguments.

The British Medical Association (BMA) welcomed the committee’s report, saying a ban on chimera or hybrid embryos would “cause serious delays to this very important research which is aimed at investigating many serious and debilitating conditions including Parkinson's and Alzheimer's disease”.

Dr Vivienne Nathanson, the association’s head of science and ethics, commented: “Given that the law already prevents such embryos being placed in a woman, and that the UK has a robust mechanism for regulating individual research projects, the BMA does not understand the Government’s current reservations on this issue. The BMA calls on the Government to permit this research, with strict controls, in the forthcoming draft Bill.”