LUN-LUN is 18 months old. But even before he was born, he was destined to be a healer in a unique project that could benefit hundreds of children. His four-year-old sister, Wong Ching-wai, who was born with the genetic disorder known as thalassaemia major, is now home after becoming the first in Hong Kong to be given a transplant of stem cells, present in the umbilical cord blood of newborn babies. Now, thanks to the transplant she will soon be free of the painful daily injections which can take up to 10 hours to complete. The success of the transplant has given parents whose children suffer from the blood disease, also known as Cooley's anaemia, new hope. Cooley's anaemia means the body fails to normally synthesise haemoglobin (the oxygen-carrying pigment in red cells), leading to severe anaemia. The only way to combat this is by monthly blood transfusions. But because constant transfusions lead to the accumulation of iron in the body, lengthy injections are required each day to get rid of the excess toxic metal. There are about 600 sufferers of thalassaemia major in Hong Kong. Two more mothers have already opted to get pregnant to give their children a new lease of life. Until recently, bone marrow transplants were the only cure for these children, as human bone marrow is rich in the special stem cells essential to cure them. But bone marrow transplants are only possible if a donor volunteers for a two-hour operation. As the special stem cells are also found in blood from the part of the umbilical cord and placenta that is discarded, the new technique proves a better alternative. But there are problems. The technique, like a bone marrow transplant, still requires matching donors. And mothers who are carriers of the defective gene run the risk of their new baby also being a sufferer of the disorder. In Hong Kong, about six per cent of the population are carriers of the related gene. Although carriers do not suffer from the disease, if both parents are carriers, there is a 25 per cent chance their children will inherit the severe form of thalassaemia. Before giving birth to Lun-lun, Ching-wai's mother had previously had an abortion because pre-natal tests showed the child to be a sufferer. She was luckier the second time. One of the pregnant mothers who had been hoping her newborn could become a healer has been told the child she is carrying, though healthy, is not a matching donor. Tests have yet to be carried out on the second mother. The associate dean of the Faculty of Medicine at the University of Hong Kong, Dr Lau Yu-lung, said counselling was a must for mothers so that they understood the pregnancy was not solely for the benefit of another child. He said it was ethical to give birth to a child as long as saving a brother or sister was not the only reason for the child's existence. According to Dr Lau, it would take an 'abnormal' couple to abort a child simply because he turned out not to be a matching donor. The chairman of the Cooley's Anaemia Association of Hong Kong, Tang Leung Yin-fun, said: 'It is ideal if the newborn can become a donor. But even if he can't, it is good for the family to have a healthy child to keep the ill one company.' Mrs Tang is a mother of four. Three of her children, aged between 16 and 21, are sufferers of the blood disorder. 'If the technique had been available earlier, I would quite readily have got pregnant to give my children a chance,' she said. 'But to abort a child is cruel. I had one abortion when I was pregnant the fifth time. Pre-natal tests were finally available then. I chose to have an abortion. I still feel bad about it. 'But it is a task handling three children with the disease.' Dr Lau said it was possible that more mothers would consider getting pregnant because of the new technique. He said while he would do his best to avoid unnecessary abortions, the answer lay in a central cord blood bank. In New York a cord blood stem cell bank has been set up with more than 3,000 samples stored. Thirteen samples have been used for transplants on unrelated patients in the US. A similar bank in Hong Kong would allow transplants to be carried out on unrelated patients. If that could be done, hopefully in two to five years, mothers would no longer need to agonise over whether they should get pregnant, and risk having to have an abortion at a later date. Dr Lau said as the umbilical cord provided a rich source of blood stem cells which could develop into different types of blood cells, transplants using umbilical cord blood could also be used to fight acute leukaemia, aplastic anaemia and immuno-deficiency. He said it was also possible that in future, not only children, but adults could benefit from the new technique.