Possible causes of MND (including inherited forms of MND)

Most people who develop MND have no family history of the condition, and it is extremely unlikely to develop in other family members. (See below for familial or inherited MND). Little is known about what causes this form of MND. It is thought that MND is caused by a mix of genetic and environmental factors, and several possible factors have been suggested, including exposure to chemicals, fractures and injuries, smoking, military service, and engaging in some sports or high levels of exercise, but research studies have so far failed to find clear conclusive evidence. Probably lots of different factors are involved, and in any one person MND is likely to occur for complex reasons, rather than there being any single cause. Several factors may increase the risk of developing MND or may help to ‘trigger’ it, but may not be enough in themselves to cause it.

Some people we talked to felt there was little point worrying about what had caused their condition or whether they had done something to cause it. Lots of people asked themselves ‘Why me?’ but at the same time many felt it was important that people should not blame themselves. Some also pointed out that it would not make any difference to their condition even if they did know what caused it.

Not even the experts know why people get MND. She knows there’s no point worrying if she did…

Age at interview 39

Gender Female

Age at diagnosis 38

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He wonders if giving up smoking after 50 years had anything to do with getting MND but his…

Age at interview 60

Gender Male

Age at diagnosis 59

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Not knowing what had caused their condition was frustrating for some people. While some could live with the idea that it was just chance, others struggled with this idea, especially if they and their families had always been very fit and healthy.

He can’t understand why both he and his wife developed MND. He thought playing a lot of sport might have had something to do with it in his case.

Age at interview 76

Gender Male

Age at diagnosis 61

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Some had done a lot of reading and searching on the internet for different theories about causes and the latest research evidence.

He has read up on suggested causes. He worked in farming and wonders whether exposure to sheep dip affected him, or whether it’s just chance.

Age at interview 60

Gender Male

Age at diagnosis 56

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People mentioned a wide variety of what they thought might be possible risk factors from their own experience, including:

  • A stressful lifestyle or particularly stressful events
  • Diet
  • Exposure to chemicals (especially in agricultural work and on food, but also when working as a firefighter and installing industrial machinery)
  • Exercise, sport and sports injuries
  • Other injury (including head injuries and leg injuries)
  • Previous chemotherapy and surgery
  • Medication for depression
  • Amalgam teeth fillings
  • Throat infections, viruses
  • Lyme disease
  • Genetics
  • Frequent travelling (including muscle cramps caused by sitting still for long periods).

She has thought of many things which might have caused her MND including injury, stress, dental…

Age at interview 63

Gender Female

Age at diagnosis 62

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She had already met her future husband at university before her father died of MND. They assumed…

Age at interview 34

Gender Female

Age at diagnosis 31

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Some people we talked to, who had younger children, worried especially about whether their MND might be an inherited form. Knowing that MND runs in the family raises particular issues for people about whether they themselves will get the condition, and whether their children and other family members will also get the condition. Gene testing is not always possible, if there is no clear family history.

So far her children have decided not to be tested for the SOD-1 gene mutation. At the moment…

Age at interview 45

Gender Female

Age at diagnosis 37

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She might not have had children if she’d known she had familial MND, but she’s glad she has them…

Age at interview 45

Gender Female

Age at diagnosis 37

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Her father did not have a known mutation so she did not have genetic testing. She had already…

Age at interview 34

Gender Female

Age at diagnosis 31

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See our resources for links to further information on research around causes of MND.

Immediate reactions to diagnosis

Getting a diagnosis of MND was a terrible shock for almost all the people we talked to. This might be mixed up with all kinds...