18 February 2013
Professor Alan Handyside is a Consultant in Pre-Implantation Genetics, Michael Summers is a Consultant in Reproductive Medicine, Dr Karen Sage is a Genetic Counsellor and Dr Alan Thornhill is Scientific Director at the Bridge Centre, London.Appeared in BioNews 693
The Human Fertilisation and Embryology Authority (HFEA) recently announced plans to review the list of approved inherited conditions for which preimplantation genetic diagnosis (PGD) is currently licensed (1) to ensure that PGD is only available for conditions which meet the statutory requirements in the UK (2). Specifically, this review will focus on the value and legitimacy of providing PGD for seven already approved conditions for which medical treatment has significantly improved since the condition was first licensed.
It would be wrong to disregard improvements in treatment for genetic conditions which benefit existing sufferers and future affected children. To this end, we suggest that clinics should be obliged to inform patients of improvements in the treatment of any condition for which PGD is offered. In most cases, this would be most effectively covered in consultation with a suitably qualified genetics professional. In this way the risks and benefits of PGD, along with alternative options, can be discussed between patient and provider as with other medical procedures. Furthermore, we welcome any opportunity to make PGD safer, more effective and more accessible for patients. However, we fear this latest exercise will achieve none of these things.
The legal test for whether PGD for a specific disorder meets the statutory requirements is: 'that there is a significant risk that a person with the abnormality will have or develop a serious physical or mental disability, a serious illness or any other serious medical condition' (2). This clearly places the word 'serious' at the heart of the issue but 'seriousness' does not necessarily equate to being 'untreatable'.
At first glance the number and choice of the seven conditions (Leber's Hereditary Optic Neuropathy/Leber's Optic Atrophy, Marfan Syndrome, Multiple Endocrine Neoplasia (type 1), Neurofibromatosis (type II), Partial Lipodystrophy Familial (type 2), Prader Willi Syndrome, Retinoblastoma) under review appears somewhat arbitrary and the selection process capricious. We note that, despite significant improvements in both the treatability and longevity of cystic fibrosis sufferers, this condition is not on the list under review. It also seems rather inconsistent to focus on potentially treatable conditions, the true severity of which in a new generation is unknown, when testing for a predisposition to breast cancer (e.g. BRCA1) is permitted despite there being no guarantee that any future child will actually be affected at all.
How truly treatable are the seven listed conditions? What is the real impact of 'treatment' on sufferers and their families? And how does 'treatable' equate with seriousness? If the purpose of the exercise is to ensure that regulatory requirements are met, the law is upheld and no embryo is ever biopsied or selected against unnecessarily, then surely this must be a continuous process which should consider all possible conditions in which any 'harm' might be done. We urge the HFEA to capture the impact of any given genetic condition not just on the patient but also on the family and future generations, especially those inherited in a dominant fashion (e.g. Marfan syndrome – which appears on the review list).
PGD has been carried out under license and stringent regulation in the UK for several decades. Where is the evidence that we have a problem? Frequently, a vast amount of multidisciplinary assessment for suitability is carried out by the time a couple complete their treatment. How many couples in the UK have undergone PGD for a single gene disorder unnecessarily? The choice to undergo PGD is ultimately a courageous one since the IVF process itself can be financially, physically and emotionally draining for couples. We should trust that couples will make informed decisions about what is right for them and their families.
Despite reassurances that this review will not necessarily lead to withdrawal of conditions from the now infamous 'PGD list', that prospect remains a real possibility. If this should occur we believe this could make pariahs of prospective PGD patients, create a 'blacklist' of some serious genetic conditions and undoubtedly force more patients to seek treatment overseas. It is almost certainly vulnerable to legal challenge.
To prohibit PGD for a heritable disorder naturally implies that it would no longer be offered through the application of prenatal testing. This is clearly not the case, so why should an embryo receive more 'protection' than a fetus? If prenatal testing is still possible for certain conditions but PGD is banned, then one of the fundamental cornerstones of PGD would be removed, i.e. avoiding the traumatic decision of termination of an affected pregnancy from patients at risk of transmitting inherited disorders.
We should all be wary when the responsibility of care shifts away from patients and providers towards a regulator with the power to decide what is serious and what is not. Fundamentally, this issue is about patient choice and quality of life. We believe patients and providers together should be allowed to choose to prevent an inherited condition in the next, and subsequent, generations rather than be paternalistically forced down the path of accepting a 'treatable' but ultimately incurable condition.
The potential severity of a condition and its treatability can only be roughly estimated – it will naturally be affected by a number of factors including genetic background, penetrance, intrauterine effects, epigenetics and life experiences. Since the 'worst case' principle applies we should accept that couples at risk of transmitting even 'treatable' conditions should have all reproductive options (including PGD) available to them.
In 2007, a case of congenital fibrosis of the extra-ocular muscles (CFEOM1) treated at the Bridge Centre received press coverage on the basis that to some it did not pass the 'serious' test for PGD. However, the prospective parents were informed, coherent and persuasive about the reasons why they did not want any future child to experience the stigma, disability (partial blindness) and numerous corrective surgeries (none of which was successful in treating the condition). No committee or regulatory body could realistically make a sound decision addressing the seriousness of the condition on their behalf. Thankfully the condition was licensed by the HFEA and treatment was carried out.
Prospective PGD patients are already in a challenging situation, having to face their chances of conceiving a healthy child potentially compromised as they wait for centre licensing, condition approvals, test development and funding. Now is not the time to be putting up new barriers. Given the understandably limited resources available to the HFEA in austere times, its priority should be to reduce PGD licensing times to meet existing targets. This would be of real and immediate benefit to patients.