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The case for case-by-case regulation of PGD: a response to Dr David King

26 January 2010
By Nick Meade
Policy Analyst, Genetic Interest Group
Appeared in BioNews 543
Dr King's few specific justifications of preserving the status quo focus on late-onset conditions, specifically that their lower penetrance, later age of onset and the availability of prophylactic treatments take the conditions to the borderline of what is considered serious. This is not the case: a condition's 'seriousness' should be assessed by its affect on a patient who has the condition; it should be considered as a serious condition with lower penetrance, or as a serious condition with a late age of onset. Breast cancer (Dr King's example) is a serious condition. Those that have the BRCA1 gene mutation have a chance between 60 per cent and 85 per cent of contracting this serious condition. If a gene confers a significant risk of contracting a serious condition then PGD should be permitted as an option for families to consider.

The age of onset and penetrance is impossible to predict accurately for individual cases. When conditions with incomplete penetrance, and varying age of onset and expressivity are considered for licensing, GIG believes that the condition should be licensed by considering the worst possible case that can be reasonably expected.

The 'treatability' of these conditions should not be considered as an argument against the use of PGD to prevent affected births, except where such a treatment will be minimally invasive, and allow the affected child to expect a normal life free from restriction. None of the late-onset conditions currently licensed for PGD have such treatments available.

My final point on late-onset conditions is the issue of time. The time delay imposed by using a case-by-case licensing process instead of a condition-by-condition licensing process is especially harmful for patients with some late-onset conditions. To return to the example of inherited cancer, one of the prophylactic treatment options available is preventative oophorectomy. This measure of course must be taken after the PGD process has been completed, and increases the need for the process to be as quick as possible. A case-by-case approach to licensing lengthens an already lengthy and difficult process.

Dr King presents no advantage to case-by-case licensing of PGD for tissue typing to conceive a saviour sibling as opposed to condition-by-condition licensing. I present a disadvantage: the time factor. The time delay imposed by using a case-by-case licensing process instead of a condition-by-condition licensing process is especially harmful for families with a sick child who could benefit from a sibling donation of cells or tissue. The affected sibling may have a very short life expectancy and, as I have already stated, the case-by-case approach to licensing lengthens the process. To maximise chances of success of such a donation delays should be minimised.

In his arguments against the use of tissue typing to conceive a saviour sibling, Dr King calls for this to be a last resort. All of those who have met a family who have or are trying to conceive a saviour sibling can assure Dr King that this is indeed the case.

GIG sees no constructive benefit gained by maintaining case-by-case licensing for either PGD for late-onset conditions or PGD involving tissue typing.

23 May 2011 - by Nishat Hyder 
The German parliament will debate the country’s law on PGD following the introduction of three separate bills on the issue. Two of the bills allow PGD under certain circumstances, the other calls for a total ban....
1 November 2010 - by MacKenna Roberts 
The European Society of Human Reproduction and Embryology (ESHRE) has published an updated set of best practice guidelines for fertility clinics on the use of preimplantation genetic diagnosis (PGD) and preimplantation genetic screening (PGS) techniques...
16 August 2010 - by Rosemary Paxman 
The successful use of PGS (preimplantation genetic screening) can be linked to access to appropriate technologies and the skill level and techniques used by embryologists, new research has found....
18 January 2010 - by Dr David King 
On 20 January, the UK's Human Fertilisation and Embryology Authority (HFEA) will decide whether to continue the case-by-case regulation of two types of preimplantation genetic diagnosis (PGD) applications: those for late onset conditions and tissue typing of embryos to produce a 'saviour sibling'....
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