Behind yesterday's announcement from the Human Fertilisation and Embryology Authority lies the tale of two families, each with a sick child whose only hope of an ordinary healthy lifespan is a bone marrow transplant.
Zain Hashmi, five, has thalassaemia, an inherited blood disorder that is fairly common in Mediterranean countries and certain other parts of the world. He needs blood transfusions every three weeks to stay alive and constant medication. The long-term prognosis is not good.
Zain was the fourth child in his family. No matching donor has been identified for the transplant he needs. His parents, Raj and Shahana Hashmi, had a fifth child, Haris, in the hope that he would be a match, but he was not. They decided to have another baby through fertility treatment, so that a number of embryos could be created that could then be tested for tissue type in the hope that one would prove a match for Zain.
The Care clinic at the Park Hospital in Nottingham sought the approval of the HFEA, which held an emergency meeting in December 2001 and after much discussion licensed the clinic to go ahead. But permission was only given in the Hashmi case because Zain's disease is inherited from his parents and it was possible that any new baby would also suffer from it.
The couple's embryos would anyway be screened for the thalassaemia gene, which requires the removal of a cell from the three-day-old eight-cell embryo. So carrying out tests for tissue type on the cell would not be an additional invasive procedure.
But a similar application by the parents of Charlie Whitaker, also five and just as seriously ill, with Diamond Blackfan anaemia, was turned down by the HFEA in August 2002. He is treated with steroids and blood transfusions, which have unpleasant side-effects. Again, his parents, Jayson and Michelle Whitaker, had a second child, Emily, who was not a tissue match, so they sought fertility treatment to have a baby who would be.
But although Charlie's condition may be inherited from his parents, there is no genetic test for it. That meant that there would be no benefit to the new baby from the invasive procedure of removing a cell from the embryo - only a benefit to Charlie. The HFEA, concerned to safeguard the welfare of the newborn child, said no.
In the end, the Whitakers went to the United States where there are no restrictions on pre-implantation genetic diagnosis and tissue typing in private clinics. A year ago, Jamie Whitaker was born, selected at embryo as a tissue match for Charlie. The family are now waiting to find out whether Jamie also has Diamond Blackfan anaemia. If not, the transplant that it is hoped will save his brother's life will go ahead.
Mr and Mrs Hashmi are still trying to conceive the baby that they hope will save Zain.
Yesterday's decision to change the rules for two-year-old Joshua Fletcher, who has the same condition as Charlie Whitaker, has much to do with the public debate over the fate of Zain and Charlie.
