Lauren donated bone marrow to her brother, helping him to survive leukaemia. But in theory a child could refuse.
Imagine your child has leukaemia, a potentially fatal cancer of the white blood cells. Doctors say his or her only chance of survival is a transplant of healthy bone marrow, taken from a brother or sister. For the healthy child, this means surgery under a general anaesthetic, a stay in hospital and a risk of complications, albeit slight. The "donor" child is frightened and reluctant to go through with it. Do you persuade him or her to do so?

Debby Harrison and her family were told in August last year by doctors that their middle child, five-year-old Lewis, had leukaemia. The disease causes an excess of white blood cells in the bone marrow, which eventually prevent vital organs from functioning. It can be treated successfully by a transplant from someone with similar tissue typing. All five members - including both parents - of the Harrison family were tissue-typed; Lewis's older sister, 10-year-old Lauren, was found to be a perfect match.

In January, Lauren had some of her bone marrow removed to help save the life of her brother. He is now thriving - out of hospital and back at school.

"Lauren said she had a feeling it was going to be her because she didn't want it to be. She was scared of hospitals and needles," says her mother. "When she found out she was a bit upset and scared, but then became very matter of fact about it, telling her friends what she was doing.

In this case, however, there was no parental pressure. "She was happy to do it. In a way, I suppose, she didn't really have a choice.

"We simply told her the facts. We didn't say, 'Look if you don't do it, Lewis will die,' because that would have been too much, but she knew as much. At the end of the day a parent isn't going to say, 'The choice is yours. If you decide not to, that's fine, we'll just prepare for our son's funeral.' If she had had very strong views against being a donor, I don't know what we would have done."

Up to 500 bone marrow transplants a year are carried out in Britain. For many people who need a bone marrow transplant - principally patients with leukaemia, who make up 90 per cent of cases - the greatest hope of a successful match lies within the family, where there is a one in four chance among siblings. Bone marrow registers, such as the British Bone Marrow Appeal and the Anthony Nolan Trust, help people who are hunting down a match outside the family, but in too many cases suitable donors are never found.

During the operation on the donor, which takes about 40 minutes, healthy bone marrow is aspirated from the iliac crest, part of the pelvic bone, using a special needle. According to a report in the Journal of Clinical Pathology, post-operative pain is modest, and easily controlled. "With care, any risk to the donor is minimal," it reads. The bone marrow cells are then transfused intravenously into the patient, whose own immune system has been destroyed to get over problems of rejection.

While most families with a very sick child would take such "altruistic" donations for granted, there is growing concern about the ethical problems involved in a child undergoing surgery for someone else's benefit. Lawyers and academics concerned with children's rights argue that under the Children Act, a medical procedure should only be carried out if it is in the best interests of the child undergoing treatment.

"Adults are not usually compelled to display altruism, but children are regularly 'volunteered' by their parents," says Linda Delaney, senior lecturer in the School of Law at Manchester Metropolitan University, who wants to seelegal safeguards established for potential child donors.

She argues that a bone marrow certification scheme should be set up in which independent witnesses would ensure that the child donor has fully consented and understands the risks involved. An independent tribunal or medical social worker could look at each proposed case of donor transplants and decide whether it is in the best interests of the child to go ahead.

"Parents may find it difficult to adjudicate fairly between their children's competing claims for protection," says Ms Delaney. "Some child donors will understand the risks and yet be eager to help. Others, however, may not so easily consider that their sibling's best interests coincide with their own."

But what exactly are the donor child's "best interests?" Doctors involved in transplant medicine are hostile to the idea that a transplant is solely for the benefit of the recipient.

Writing in the British Medical Journal, Dr Stacy Month, a paediatric oncologist from California, says: "We're not simply talking about a few days of feeling good because one helped out. We're talking about saving the life of one's brother or sister. The donor could benefit immensely from many years of a 'whole' family. The death of a sibling is an overwhelmingly tragic event, with severe psychological repercussions on all family members for the rest of their lives."

Dr Month also argues: "A far more compelling issue is whether a parent is acting in the best interest of the ill child. Some paediatric bone marrow recipients suffer immensely because of the side-effects and complications of a transplant that has almost no chance of success."

Ray Powles, head of leukaemia and bone marrow transplantation at the Royal Marsden, who carried out the first successful child donor transplant 23 years ago, says: "I have performed around 1,500 transplants, 1,000 of which have been between brothers and sisters. We are not aware of any adverse effects to the donor. In a transplant you take around 2 per cent of the marrow and the donor child has probably made that up by the same evening, because it is an organ that has enormous flexibility, unlike a kidney."

Mr Powles say he is also unaware of any sibling who has refused to go ahead with a bone marrow donation. "I have a young family with children aged seven to 14, and I have also spent my life transplanting. If my 14-year-old boy had leukaemia, I could handle the idea of my daughter being a donor very easily."

Lauren Harrison has no regrets. "I'm glad it's all finished. My brother is a lot better now, and I can play with him. But I still really don't like needles."

Twenty-three years on, 'nothing could be better'

The first successful child donor transplant in Europe took place at the Royal Marsden Hospital 23 years ago, when Ian Cuneen, then seven, received bone marrow from his sister, Clare.

"I was diagnosed as having aplastic anaemia [a rare blood disorder caused by failure of the bone marrow]," he recalls. "All of the family were tested and Clare was the perfect match. If she hadn't done it, I wouldn't be here now, I'd be dead. I'm completely clear now and nothing could be better."

His sister, now Clare Brown, was 13 at the time. "I don't think it was a case of volunteering, it was just something you did," she says.

Their daughter was dying, they couldn't find a donor. So they created one

An American couple conceived a baby to give their sick teenage daughter the chance of a bone marrow transplant. Abe Ayala and his wife, Mary, decided to have another baby because of the one in four chance that the infant could provide a suitable bone marrow for their 17-year- old daughter, Anissa, who suffered from leukaemia. The couple had looked for a suitable donor for more than two years without any success. Neither of the parents, nor their 19-year-old son, was suitable.

The couple went ahead with the baby two years ago, and their daughter has since undergone a successful transplant using bone marrow from her newborn sister.

The Ayalas's case has created a furore in the US, with some critics arguing that creating a child to provide spare parts for another human is unethical.

A spokesman for the City of Hope Medical Centre in California, where the operation was carried out, says: "There is certainly a feeling that this has been done before, but that people just haven't come out and said it."

Even if it was ethically acceptable, says Ray Powles, head of leukaemia and bone marrow transplantation at the Royal Marsden Hospital, the Ayalas's solution may not be suitable in many cases. "With malignant disease, you really need to get on with it," he says. "There is a long time delay in having a baby and by the time you are ready to transplant, the child may be dead."