Deciding whether to have pre-symptomatic genetic testing: Reasons for not wanting to know (yet)

Pre-symptomatic genetic testing is available for some people who do not currently have symptoms of MND but have an increased chance of developing it in the future. This section covers:

  • Coming to a decision on pre-symptomatic genetic testing for inherited MND
  • Deciding not to have pre-symptomatic genetic testing for inherited MND- reasons for not wanting to know (yet)
  • Pre-symptomatic genetic testing as an ongoing decision

Pre-symptomatic genetic testing (sometimes called ‘predictive testing’) is generally only offered where a genetic variant linked to inherited MND has already been identified in an affected relative. It allows people without symptoms to find out if they have inherited this particular gene variant. Deciding whether to have pre-symptomatic genetic testing is an individual choice, with many factors involved.

Coming to a decision on pre-symptomatic genetic testing for inherited MND

Overall, people had different experiences of coming to a decision on pre-symptomatic genetic testing. People sometimes knew immediately that they did not want to have the genetic test at present. Richard made the decision “pretty much instantaneously”. Joe described it as a quick and self-evident decision.

Joe’s mum asked him whether he would be interested in having pre-symptomatic genetic testing. He didn’t have to think about his answer, but “just knew” he didn’t want to know.

For other people who didn’t want to know yet, it took a while to weigh up what they wanted. A few people we spoke to described going back and forth. Karen had times when she thought she might like to know. She explained how talking to others played a role in her decision, “sometimes I think, ‘Oh, I think I might get tested, I might find out’, but then I’ll talk to people… and most people say, ‘No, don’t’”.

Other people hadn’t yet made a decision on whether to have the pre-symptomatic genetic test or saw it as an ongoing decision which could change, which will be covered below. People who decided to have pre-symptomatic genetic testing also came to the decision in different ways.

Deciding not to have pre-symptomatic genetic testing for inherited MND- reasons for not wanting to know (yet)

People we interviewed spoke of a range of reasons for not wanting to have the pre-symptomatic genetic test at present.

Whilst receiving a negative result would be “amazing”, “phenomenal” and “life changing”, the possibility of testing positive was a concern. Some people believed that taking the test wasn’t worth the risk of being told they carried a genetic variant of inherited MND. Taking the genetic test was compared to tossing a coin, rolling the dice, or playing “Russian roulette”. Georgia Y’s decision was based on how she was currently affected by knowing she was at an increased risk of developing MND. She saw taking the test as “such a risk for me. As it’s not affecting me, it’s just not worth it. But if it was, it probably would be”.

People felt that not having the genetic test allowed them to hope that they hadn’t inherited the gene variant linked to MND. Karen pointed out, “if I knew that I had the faulty gene, there’s no way back from that”.

Although she describes herself as “a bit of a pessimist”, not knowing whether she has inherited the C9orf72 gene variant allows Karen to hold on to hope.

Other people found the idea of knowing what could happen in the future to be “pretty grim”. Angi said, “why do I want to know if there’s a bomb going to go off?”, and Lexi saw knowing the results as “quite a finality for me”. Liz Z did not want to know what illnesses she could develop. She said, “if you look hard enough, you’ll find something wrong with most people. Is that really the way we want to live our lives? I don’t think so”. Joe felt that knowing could have a negative impact.

Joe felt that receiving a positive pre-symptomatic genetic testing result “would mess with us”. In his mind, that would mean his “days are numbered”.

Other people we interviewed were also concerned about the potential emotional and mental health impact of knowing they carried a gene variant associated with inherited MND. Lexi said, “I just want to enjoy my life, I don’t want to have this hanging over me…I think I can cope with it a lot better not knowing”. Paul felt that knowing he carried the genetic variant would be “putting myself under an unnecessary cloud”, where the possibility of developing MND would be at the forefront of his mind. Some people thought that receiving a positive test result would make them worry about possible symptoms. Liz Z felt she would be “even more anxious and more hypervigilant, and I’m bad enough as it is”.

Richard worried that finding out he carried the C9orf72 gene variant would put him in a “dark space” every time he felt that something wasn’t right.

For Richard, having got into a positive mindset where he felt able to cope, he didn’t want to revisit the decision not to have the pre-symptomatic genetic test. Georgia Y also felt reluctant to think about testing, “I try really hard not to get this too in my mind, because I just don’t want it to plague my thoughts”.

Other people we spoke to felt unsure of how they would respond to a positive result. William had worries about how he would react but also about the impact on family members.

William would be concerned about the mental health impact of finding out he carried a gene variant linked to inherited MND. Knowing could be distressing for him and his family.

People with children were aware of the possible impact of genetic testing on them. Karen questioned the implications for her daughter, who didn’t want to think about the possibility of being affected or know if either of them carried the gene variant. Stage of life was an important consideration for people when thinking about pre-symptomatic genetic testing. Some people might have considered testing if they hadn’t had children already when they found out about inherited MND in the family.

Another potential impact people worried about was on securing a mortgage or getting insurance. One individual had come across a question on a life insurance form about his medical history. He said, “I’d rather not know because the minute you put something like that down, they’re just going to ram your premium straight up”. Although it is important to be honest when asked questions by insurance companies about one’s own or a family member’s medical history, Genetic Alliance UK advises that people in the UK do not have to disclose predictive test results for inherited MND.

Other individuals we interviewed questioned the point or benefit of pre-symptomatic genetic testing. They couldn’t see any advantages or didn’t think knowing would add value to their lives. Some people didn’t feel it offered useful information, or enough certainty over the future. A key reason for this was the current lack of long-term treatment or cure.

Having pre-symptomatic genetic testing would only change Georgia Y’s life in “negative ways”. She feels she would worry more, yet there would be nothing she could do about it.

Dani felt there was no point in having pre-symptomatic genetic testing and “terrorising myself”. Although she has since been diagnosed with MND, she looks back on this as the right decision.

People pointed out that even if they tested positive for a genetic variant linked to inherited MND, they might never develop symptoms. Furthermore, it wouldn’t provide information on when symptoms would develop, if at all, or what the symptoms would be. As William said, “I wouldn’t anticipate getting an easy to deal with, black and white answer”. Paul points out that we can’t control the future.

The future is uncontrollable, so Paul would rather focus on making the most of life. He emphasises that “it’s not just MND that can blight older life”.

Robyn, who has health anxiety, felt that whatever the outcome of the genetic test, she would worry, “If I don’t have it…I’ll still worry about everything else. And then if I do have the gene, then I’ll just worry about that and everything else, so what’s the point”.

Like Paul, other people also felt that knowing their genetic status would not change how they lived their lives. Georgia Y tries to make the most of life as it is, and Karen also says she behaves like she has inherited the gene variant anyway. Liz Z tries to live by the saying, “plan for the worst, hope for the best”. She tries to live in the present but has also done some planning for the future, so she is prepared if she were to develop symptoms. Unlike some people we spoke to, Mary thought that knowing her genetic status might change how she lived her life.

Part of Mary wishes she could have pre-symptomatic genetic testing, but she points out that whatever the result, the future is uncertain.

Like Mary, other people we spoke to were also in the situation where a genetic cause of the disease in their family had not been identified. This was because their relative with MND had not had genetic testing or had tested negative for the genetic variants that had been identified at the time. This was the case for Liz Z and her sister, who had asked about pre-symptomatic genetic testing at a meeting for families affected by inherited MND. They had been told it “wasn’t worth having”, but not everyone had been told that it might not be available to them. Mary felt that she didn’t know enough about genetic testing to know “what are the advantages or disadvantages?”

Pre-symptomatic genetic testing as an ongoing decision

A few people we spoke to felt conflicted or unsure of whether to have pre-symptomatic genetic testing.

Sam has “flip-flopped” between a decision on pre-symptomatic genetic testing. Having “come full circle”, they now question whether it is “worth the risk” of taking the test.

Although she doesn’t want to have presymptomatic genetic testing now, Louisa has “no idea whether or not I’ll get tested in my lifetime”.

Some people who had decided not to have genetic testing felt that this was something they might come back to in the future, particularly if there was a point where knowing would be of benefit. As Liz Z said, “until there’s a reason, I’m not going to poke the hornet’s nest”. Factors and scenarios which might encourage them to reconsider their decision included:

  • if a treatment was available to prevent or delay the disease (although Lexi felt a treatment to delay progression would not change her mind- “until I know that I can have that defective gene chopped out…I’m not interested”)
  • to aid research on finding a cure or participate in a clinical trial
  • if their partner wanted to know or if it would benefit their family
  • to inform their children’s decisions about starting families of their own
  • to inform decisions on talking to children about their own genetic risk.

This was an important factor for Louisa, who questioned whether she should “burden” her child with this information, “or do I get a test myself and see if I need to?”

Paul sees presymptomatic genetic testing as a decision that is “continually under review”.

Other people we spoke to would consider genetic testing if they were showing symptoms or were diagnosed with MND. Richard hoped this might lead to a quicker diagnosis, and Liz felt that having this information could benefit her daughter. However, not everyone felt the same. Angi felt that nothing would make her consider having genetic testing.