NIPT can be used to test for other, rare genetic conditions. Some of these conditions run in families, such as cystic fibrosis and Duchenne muscular dystrophy; some arise at the time of conception, such as thanatophoric dysplasia.
Pregnant women with a family history of a genetic condition, or whose fetus has been found to have an anomaly on a scan, are usually referred to a specialist genetic testing service by their obstetrician, midwife or GP.
Until recently, if it is suspected that a fetus has a rare genetic condition, the only option for women and couples seeking a diagnosis would be to have an invasive test such as amniocentesis or CVS, which carry a small risk of miscarriage. However, NIPT can now be used to test safely for some conditions if they are inherited from the father or arise at conception. NIPT for these conditions can usually be carried out earlier than invasive testing and is often diagnostic, removing the need for invasive testing altogether.
There are currently no UK-specific guidelines for healthcare professionals on offering NIPT through specialist genetics testing services. Decisions about what tests should be offered, and to which patients, are made on a case-by-case basis by doctors such as clinical geneticists.
In addition to the benefits offered by NIPT, the people and organisations we spoke to during our project suggested that the increasing use of NIPT for rare genetic conditions in the NHS raises a number of issues that require consideration:
Implications for the NHS
As NIPT for rare genetic conditions becomes more widely available, genetic counselling services will need to grow to meet the information and support needs of those undergoing testing.
Information and support
NIPT could uncover unanticipated or secondary findings relating to the pregnant
woman, such as information about a genetic condition that the woman has, or the presence of cancer. Women should be counselled about the possibility of such findings during the consent process. They should also be aware that NIPT may fail to produce any results, or produce inconclusive results, which could lead to a delay in diagnosis.
Implications for people with genetic conditions
Introducing NIPT on the NHS is likely to lead to an increase in the number of diagnoses of rare genetic conditions, and possibly an increase in terminations. This gives rise to concerns similar to those raised by NIPT for aneuploidies. For example, that it might send out negative messages about the value of people with genetic conditions, and make them and their families more vulnerable to discrimination, stigma or abuse.
Possible future developments
This is a rapidly moving field and uses of NIPT for other single gene conditions, or ‘panel tests’ for several related conditions, are likely to be developed in future. The availability of NIPT for significant medical conditions or impairments can enable pregnant women and couples to make informed choices about their pregnancies regarding whether to continue and prepare for the birth of a disabled child or whether to have a termination.
It is also possible that NIPT could be developed in future to test fetuses for genetic conditions that are likely to affect them only in adulthood, or to test whether a fetus carries a copy of a gene that does not cause a condition on its own but might do so in future generations. Whole genome sequencing using NIPT might also become available to pregnant women and couples, where it is suspected that the fetus has a genetic condition but the origin is unknown. Making decisions about whether NIPT should be offered for this kind of use and who it should be offered to will involve consideration of:
- how best to respect the autonomy and protect the interests of the future child or adult, particularly where a test makes available detailed genetic information about them, or reveals that they are likely to develop a serious genetic condition later in life;
- whether the information being sought is medically useful; NIPT for rare genetic conditions in the NHS
- whether NIPT might inadvertently reveal previously unknown genetic information about the pregnant woman or her partner; and
- what genetic counselling and support will be available to women and couples undergoing testing.
What is a ‘significant medical condition or impairment’?
We use the term ‘significant medical condition or impairment’ in this report to describe what would be grounds for termination under section 1(1)(d) of the Abortion Act 1967 (the ‘fetal anomaly ground’). We recognise that what constitutes a significant medical condition or impairment is a judgement that depends on several factors, including the likely level of impairment, the available treatment options, and the views of and potential impact on the family and the individual themselves. In this report, we refer to ‘less significant medical conditions or impairments’ as those that would not have a significant impact on the life of the child or family, or where remedial treatment is available, and would not usually be considered grounds for termination.
For more information, see Chapter 3 of the full report