Another UK couple has received permission to try and conceive a 'saviour sibling' to provide cord blood stem cells to help treat their seriously ill child. Charlie and Catherine Mariethoz, from Leicester, have been granted a licence from the Human Fertilisation and Embryology Authority (HFEA) to use PGD to conceive a baby who can provide tissue-matched cells for their daughter. Twenty-month old Charlotte has Diamond Blackfan Anaemia (DBA), a rare blood disorder that can currently only be treated with repeated blood transfusions, but which could potentially be cured with a blood stem cell transplant.
If successful, Charlotte will be one of the first children in the UK to benefit from the approach. In September 2004, the HFEA granted Joe and Julie Fletcher permission to create a tissue-matched baby to help treat their son Joshua, who also has DBA. The decision followed the HFEA's policy change in this area, allowing couples to use PGD for testing IVF embryos solely to check their suitability as a potential cord blood donor for an existing sick child. Before that time, it had only authorised the use of PGD for establishing tissue type if it was also being used to check for a gene mutation. Some cases of DBA are caused by a mutation in a gene called RPS19, but for most - including Joshua Fletcher and Charlotte Mariethoz - the trigger remains unknown.
Jodie Fletcher, born in July 2005, was found to be a perfect genetic match for her then three-year old brother Joshua. Although Jodie is the first 'saviour sibling' conceived in the UK, another British baby has already helped his older brother in this way. In 2002, the HFEA turned down a request from the Whitaker family, who were also seeking to use PGD to conceive a tissue-matched baby to help a sibling with DBA. Michelle and Jayson Whitaker later travelled to Chicago to conceive their son James, born in June 2003, whose umbilical cord stem cells have now been successfully used to help treat their son Charlie. Following its decision to allow the Fletchers to try and conceive a saviour sibling, the HFEA said that future applications for the treatment would be looked at according to their 'individual merit'.
Mrs Mariethoz said she and her husband had always planned to have a brother or sister for Charlotte, and that the embryo testing treatment was the only way to help her daughter. 'There are still many hurdles to go over with IVF but the main thing is that we have got the licence and we don't have to go to the USA for treatment', she said. However, she added that 'it is an expensive process. It could cost up to £7,000 a go and could take as many as ten attempts to find a match, so we are really only at the foot of the mountain'. The Mariethoz family has set up the Charlotte Challenge Appeal to raise the thousands of pounds that could be needed for the treatment.
Meanwhile, according to news reports, the HFEA is expected to approve the use of PGD for detecting gene mutations that confer an increased risk of cancer. It will discuss a recommendation by its ethics committee that PGD for hereditary breast and other cancers should be allowed at its open meeting this Wednesday.