Preimplantation genetic diagnosis and the HFEA’s role
Last Reviewed 11/04/2019
By Stevan Cirkovic, Policy Officer at the HFEA
The Human Fertilisation and Embryology Authority (HFEA) is the UK’s independent fertility regulator. This blog was written by Stevan Cirkovic, Policy Officer at the HFEA – here he talks about the HFEA’s role in relation to preimplantation genetic diagnosis (PGD). If you’d like to know more about the recently completed review of PGD conditions, please see part two of this series.
What is PGD? Who is it for?
PGD is a technique used with in vitro fertilisation (IVF) that may be an option for people who have a diagnosis of a serious inherited disease in their family and who wish to avoid passing it on to their future children. IVF is the process of fertilization by extracting eggs, retrieving a sperm sample, and manually combining them in a laboratory, and is usually used to help people with fertility problems have a baby. PGD involves checking the genes or chromosomes of embryos created by IVF for a specific genetic condition. Because the embryos need to be tested in a lab, a person using PGD needs to use IVF, even if they have no fertility problems. Any embryo which has been tested and is free of the condition may then be placed into the womb. Your doctor may discuss PGD with you if:
- you have ended previous pregnancies because of a serious genetic condition
- you already have a child with a serious genetic condition and want to avoid this for a future child
- you have a family history of a serious genetic condition, or you have a family history of chromosome problems.
What is the HFEA’s role in relation to PGD?
The HFEA is responsible for licensing clinics which carry out PGD and authorising the conditions it can be used for, which must meet specific legal criteria. When assessing whether those criteria are met, we consider a range of factors, including clinical and legal expert advice as well as patient feedback. The HFEA has recently reviewed the authorised conditions as part of a regular five-yearly review process.
What genetic conditions can be tested for during PGD?
Clinics cannot test embryos for a condition unless that condition is on the approved PGD list.
Under the law, the HFEA must be ‘satisfied’ that embryo testing is carried out only where there is a ‘significant risk’ that a child born with the condition in question would have or could develop a ‘serious’ medical condition. It is the HFEA’s responsibility by law to assess whether a condition meets these criteria. Currently there are over 500 conditions that have been approved for testing.
Some patients are affected by conditions that aren’t yet authorised for PGD. In this instance, an application for the authorisation of testing for that condition can be made by your IVF clinic to HFEA, with input from your genetic consultant. A decision by HFEA is usually reached within 2-3 months.
Tip: You can find a PGD licensed clinic by using our clinic search function and filtering for PGD under ‘Screening services’ on the right.
How does the HFEA authorise conditions for PGD?
The first step involves a formal application from a PGD licensed clinic in the UK that is working with an affected patient. This will then be considered by a committee of the HFEA, called the Statutory Approvals Committee.
In their application the clinic outlines what the condition is and how it affects lifespan and quality of life of those living with it. Their assessment must clearly state how the condition meets the legal criteria. This assessment is then considered by an independent geneticist who will review the relevant scientific literature and provide a peer review.
The HFEA also works with Genetic Alliance UK to gather insights from patients living with the condition and their carers. Patient experience and views may provide the committee with an additional understanding of how serious a condition is for the people affected.
First, we assess the penetrance of the mutation; the risk of showing symptoms of a disease if you have the mutation. In this step we ask if everyone with this specific DNA mutation, or just a portion of the people, will go on to be affected by the genetic condition.
We then assess the seriousness using a number of criteria:
- Age of onset: Do the symptoms of the condition present at birth or later in life?
- Symptoms: Are the symptoms of the condition fatal, life-threatening, or do they reduce life expectancy? How do symptoms vary in their intensity between families?
- Quality of life: How quickly does someone worsen once the condition presents? And what is the extent of any physical or intellectual impairment?
- Treatability: Are there treatments available? If so, to what extent are the symptoms mitigated? And how invasive is the treatment itself?
We approve conditions based on a ‘worst-case scenario’. Once a condition is approved by the HFEA, it still remains an individual assessment and requires a decision by the geneticist and the patients whether or not to go ahead with PGD.
- Part two – The HFEA’s preimplantation genetic diagnosis conditions review
- List of all conditions approved and currently being considered for PGD
- Key facts about PGD
If you have any questions about the HFEA’s role in relation to PGD please get in touch with us at [email protected].