Lay summary by Dr Jade Howard, reviewed by Dr Scott Allen and an MND lay panel
Background
In a minority of people with motor neuron disease (MND) (also known as amyotrophic lateral sclerosis – ALS) their condition can be linked to a change in a known gene. Genes are instructions we inherit from our parents that make our bodies work and grow, but when they have changes or mistakes this can cause or contribute to certain illnesses – in this case MND. Where a gene change has been identified in a person with MND, their family members can have a predictive test which looks at their genes to see if they have inherited this change and have an increased chance of developing symptoms. This paper looks at how people at risk of MND in the US made predictive test decisions; the impact of predictive testing on how they saw their risk; how they adapted emotionally; whether they regretted their choice; and their social support.
Why is the study important?
Clinical trials targeting genetic forms of MND are ongoing and there is now a trial recruiting people who carry a particular gene but have not developed symptoms. As trials continue to make progress, it has been suggested that interest in predictive testing could increase. This paper contributes to knowledge on peoples’ experiences of predictive testing and its impacts and offers suggestions for guidelines and support.
What did the authors do and how did they do it?
The authors carried out a survey to look at people’s experiences living with risk of MND and predictive testing. 90 participants completed the survey, including 42 who had chosen to have predictive testing. Of the 42, 28 had been told they had inherited a gene change and had an increased risk of developing MND (a positive result), 11 had been told they had not inherited it (a negative result), and 3 were waiting for their result. The remaining 48 had decided not to have predictive testing. Survey responses were analysed using statistical techniques.
What are the results?
People who decided not to have predictive testing felt there were more drawbacks to testing, most significantly the lack of cure for MND. They rated the benefits of testing as less important than people who had had predictive testing, who valued being able to arrange personal affairs, know more about their risk in case treatments became available, and being able to put their mind at ease if negative.
People who tested positive described experiencing more negativity, uncertainty and psychological impacts. However, individuals who had not had predictive testing reported thinking about their risk the most, describing doing so multiple times per day, and experiencing more regret than people who had decided to have a predictive test. People who tested positive described thinking about their MND risk at least weekly, though those who tested negative mostly never thought about it.
Participants relied on family members the most when processing their risk or their genetic test result. However, there were differences between who the groups shared their genetic test results with, with some people who tested positive reporting that they did not tell their siblings this news. Although a person’s risk does not change depending on their siblings’ test results, this information may be relevant for them.
What do the findings mean going forward for people with the disease?
Although the study includes quite small numbers of each participant group (42 people who had had predictive testing and 48 who had not), it adds to understandings on experiences of living with genetic risk of MND and predictive testing. Notably, this study took place in a US context and more research is needed amongst a UK population.
Findings can also be used to guide genetic counselling practices. People receiving positive predictive test results may experience psychological impacts including negativity and uncertainty, which they should be made aware of when making testing decisions so they can plan support. Given people who have not tested also described negative impacts related to living risk (with some thinking about it every day), they may also benefit from support. Additionally, genetic counsellors could help with family communication.
This study can be found at
www.onlinelibrary.wiley.com/doi/full/10.1002/jgc4.1890
Paper title
Individuals’ experiences in genetic counselling and predictive testing for familial amyotrophic lateral sclerosis
Lead author
Connolly G. Steigerwald, Elizabeth A. Harrington
Publication details including date of publication
Research article published in Journal of Genetic Counseling in March 2024