A woman from Tasmania is 14 weeks pregnant with a baby that could eventually help to save the life of its ill brother. The parents of a four-year-old boy with an inherited immune system disorder travelled to the Sydney IVF clinic, in order to conceive a child who could provide their son with a tissue-matched cord blood transplant. The boy, known as 'BJ', has Hyper IgM syndrome, an incurable immune deficiency that leaves him prone to infections. Although he is currently responding well to conventional treatment, a blood stem cell transplant from a matched donor could offer the chance of a permanent cure.
Doctors at the clinic tested IVF embryos created using egg and sperm from BJ's parents, and used PGD (preimplantation genetic diagnosis) to select an embryo that was both free from the condition, and a tissue match for their son. Blood from the umbilical cord will be stored after the birth of the baby, which is due in August, and kept until it is needed. The boy's mother, Leanne, said that she and her husband Stephen had always planned to have another child, and that the stored cord blood will be 'insurance' for BJ.
The clinic is reported to be treating six other couples who want to conceive a healthy 'saviour sibling', and one other woman is already pregnant with a baby who will be able to provide cord blood cells to treat a child with leukaemia. Another couple are undergoing the procedure in order to have a tissue-matched baby to help treat their daughter, who has Diamond-Blackfan anaemia. Dipika and Paresh Vara should learn this week whether their second attempt to have a baby to help six-year-old Anisha has been a success.
Commenting on the use of PGD to establish tissue-type, Bill Glasson, president of the Australian Medical Association (AMA), said: 'The AMA would not sanction the selection of an embryo simply to produce a child exclusively to help treat an existing sibling'. But he added that if the intent was to create another child that is disease free and that could help the sibling, 'then it could be argued that is ethically correct'.
Last year, UK couple Michelle and Jayson Whitaker traveled to Chicago to have similar treatment to conceive their son James. His cord blood will be used to help treat their other son Charlie, who, like Anisha Vara, has Diamond-Blackfan anaemia. The Human Fertilisation and Embryology Authority (HFEA) refused the Whitakers permission to have treatment in the UK, because the couple wanted to use PGD to test for tissue type only. Some cases of Diamond-Blackfan anaemia are caused by a mutation in a known gene, but for most, including Charlie Whitaker, the gene or trigger responsible remains unknown. This means that the Whitakers could only use PGD to establish tissue type, and not to find out whether an embryo was disease-free.
The HFEA had previously granted permission for the Hashmi family to conceive a tissue-matched baby free from thalassaemia, the disease that affects their son Zain. The Hashmis were allowed to have the treatment in the UK that was denied to the Whitakers, because the Hashmis were using PGD to select an embryo free from disease, as well as for a particular tissue type. However, the Hashmis have not yet conceived such a child, and currently face a second legal challenge to the HFEA's decision, by the pro-life group Comment on Reproductive Ethics (CORE).
Sources and References
Baby created to cure brother
Seven children wait for their IVF sibling