The legal barriers that prevent a couple creating a designer baby to help save the life of an existing sick child were swept away yesterday when the human fertilisation and embryology authority announced it was prepared to allow it, subject to the merits of each case.
The decision will outrage pro-life campaigners, who fear that babies could be bred for spare parts.
But it spells hope for the Hashmi family, whose two-year-old son Zain suffers from the blood disorder thalassaemia beta and will die without a perfectly matched bone marrow transplant.
A fertility clinic in Nottinghamshire triggered the HFEA's review of the issues by putting in an application to be allowed not only to carry out pre-implantation genetic diagnosis (PGD) on embryos from Shahana and Raj Hashmi to ensure they have a baby free of the disease, but also tissue typing. Tissue typing would identify which - if any - of the embryos created by test tube fertility techniques is a perfect blood match for Zain.
As far as the Hashmis are concerned, this is their only chance. Neither parent nor any of their other five children is a match.
The application is being sped through and is likely to be decided after Christmas, because Mrs Hashmi is already 37 - an age at which a woman's fertility is fast declining.
Announcing the decision in principle, Ruth Deech, chairman of the HFEA, said: "We have considered the ethical, medical and technical implications of this treatment very carefully indeed. Where PGD is already being undertaken we can see how the use of tissue typing to save the life of a sibling could be justified. We would see this happening only in very rare circumstances and under strict controls."
However, although the HFEA is prepared to allow the transplant of umbilical cord blood cells - which could allow Zain and children like him to lead a normal life - it is not prepared to allow the newborn baby to be used as a donor of bone marrow if the cord blood transfer is not effective. The baby would have the same protection under the law as any other baby. "The wishes of the parents alone would be insufficient in deciding whether or not such a donation could be made," said the HFEA in a statement.
There will be strict conditions attached to any licence, the HFEA said.
The condition of the sick child must be life-threatening, the recipient of the baby's cord blood must not be a parent, there must be no genetic modification of any embryos, all other options for the sick child must have been exhausted, and the couple must undergo counselling.
Staff at the centre for assisted reproduction at Nottinghamshire's Park Hospital, which put in the application, were delighted. "We are pleased that the HFEA are to allow tissue typing in principle," said Ken Dowell, its medical director. "Mr and Mrs Hashmi have a long journey ahead of them but this decision is a step in the right direction."
The tissue typing tests are carried out on the same single cell from a six to 10 cell embryo that has been removed for pre-implantation genetic diagnosis. The work is complicated however, and the Park does not have the facilities to do it itself.
It has already sent off blood and skin tests from the Hashmi family members to the United States, where the work will be done.
Until now, couples desperate enough to go down this road were forced to have the tests and the IVF treatment in the US. The family of Molly Nash, six, crossed the Atlantic to conceive a baby whose bone marrow was transplanted into his sister. Molly Nash was suffering from Fanconi anaemia and would otherwise have died.
The Park has two other couples who would like to be considered for a licence to undergo tissue typing, and there are more at other centres.
Thalassaemia beta is a particular problem in families of Middle Eastern and Mediterranean origin.
