Facts and regulations

When parents need a matching donor for a seriously ill child, they can try to produce one by using reproductive technologies. Preimplantation genetic diagnosis (PGD) following in vitro fertilisation (IVF) reveals an embryo’s immune – human leucocyte antigen (HLA) – profile and whether or not it could become a suitable donor for its existing sibling. In a favourable case, a healthy and matching embryo can be implanted in the potential mother’s uterus and if all goes well, a suitable donor is born. Stem cells are retrieved by collecting placental or umbilical cord blood and these are injected into the ailing child in the hope of providing a cure. Donation of blood, bone marrow, and organs is also a viable option for other treatments that may be required later.

The conditions for which healthy matching donors have been sought so far include Fanconi’s anaemia, thalassaemia, and Diamond–Blackfan anaemia (DBA), all diseases with bleak prognoses if stem cell therapies enabled by saviour siblings cannot be used. Fanconi’s anaemia causes shortness, skeletal anomalies, tumours, leukaemias, and bone marrow ­failure; some forms of thalassaemia require constant heavy medication and regular blood transfusions; and DBA is associated with congenital malformations, thumb and upper limb abnormalities, cardiac defects, urogenital deformities, and cleft palate. Successful treatments have been reported at least in the United States, in the United Kingdom, and Belgium. Widely reported cases in the saviour sibling discussion are those of the Nash family in Colorado, United States (the first saviour sibling, provided a successful cure for Fanconi’s anaemia in 2000); in Great Britain, the Hashmi family (legal battle to produce a saviour sibling for thalassaemia (2000–2005), family stopped trying in 2004); the Whitaker family (travelled to Chicago in 2002 to produce a matching donor for DBA); and the Fletcher family (the first British saviour sibling, donor for DBA, born in 2005).