The passage through Parliament of amendments to the 1990 Human Fertilisation and Embryology Act is causing much debate at the moment.
One aspect of the Bill relevant to the CGD community is the further strengthening in law of the use of preimplantation diagnosis (PGD) and its use to select for 'saviour siblings'. PGD is used during in vitro fertilisation to determine if a resulting child will have or develop a serious medical condition. 'Saviour sibling' is a term used to describe a child born as a result of an embryo selected, through PGD, because it has a specific 'tissue type'. The tissue type of the embryo is chosen because it matches that of a sick older sibling who requires cells - usually cells from bone marrow or cord blood - to treat a serious medical condition. A case of a CGD saviour sibling has recently been reported from a centre in Switzerland.
Embryo testing for tissue type is only done where no existing stem cell donor is available and has to be done on licence from the HFE Authority (HFEA). Each application to the HFEA is considered on its own merits and the HFEA grants a licence only where it is convinced that the child will be a valued member of the family and that tissue from the child is the only means of treating the older sibling.
In a landmark case in 2005 the Law Lords upheld an earlier court decision that the HFEA acted lawfully in permitting a family to use preimplantation tissue typing to select tissue matched embryos for their son. There is much controversy about the use of such selection techniques. In practice, these are only used for life-threatening blood conditions and have only happened in a small number of cases. The HFEA has to date licenced tissue typing for six families and the technology has resulted in children being cured from serious medical conditions.
The proposed amendments aim to make the HFEA's power to licence tissue-typing of embryos unambiguous and clear in law. The Bill going through Parliament introduces into the 1990 Act five purposes for which embryos can be tested. These are listed below for your information:
1. to determine whether the embryo has a genetic abnormality that would affect its ability to result in a pregnancy. This is sometimes referred to as preimplantation genetic screening - PGS.
2. to determine whether the embryo has inherited a gene - or genes - from one or both parents that will mean that any resulting child will have or develop a serious medical condition. This is preimplantation genetic diagnosis - PGD. (In the UK, this is possible for CGD.)
3. to determine the sex of the embryo where there is a particular risk that any resulting child will have or develop a gender related serious medical condition.
4. to determine the tissue type of embryo where there is an older sibling with a serious medical condition that could be treated with umbilical cord blood, bone marrow or other tissue (excluding whole organs) or the resulting child,
5. to test in the event that there is uncertainty as to whose gametes were used to create the embryo.
Further information
What is Preimplantation Genetic Diagnosis? www.cgd.org.uk/news/news_pgdsw
April 2005
'Lords back 'designer baby' choice'http://genome.wellcome.ac.uk/doc_WTD02969.html
IMPORTANT NOTE :
The information contained on this website is intended only as a guideline, not as a substitute for medical advice. Always consult your doctor if you or your child has any CGD symptoms or concerns.
© 2001-2007 The Chronic Granulomatous Disorder (CGD) Research Trust
Registered Charity No. 1003425 email:cgd@cgdrt.co.uk
The CGD Research Trust is a member of the Association of Medical Research Charities (AMRC), the Genetic Interest Group (GiG) and an associate member of the International Patient Organisation of Primary Immunodeficiencies (IPOPI)
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