It is still not possible to give a clear answer about the precise causes of MND as each individual may be affected by a different combination of triggers. However, when you are being diagnosed, a neurological consultant will probably ask you about any family history of MND or of frontotemporal dementia (FTD). If not, it is worth asking the consultant to discuss family history, as this may help determine if an inherited gene is one of the likely factors.
MND with no apparent family history:
Most cases of MND occur with no apparent family history of the disease and the precise causes in these instances are not yet known. Multiple genetic and environmental triggers are thought to be involved, with genes playing a small role. The environmental triggers may be different for each individual, so there is no simple way of identifying what may have played a role in the onset of the disease.
MND where there is a family history:
In a small number of cases, there is a family history and the genetic input is more significant. Where this occurs, the disease is caused by a mistake in the genetic code which can be passed down, although other triggers may still be necessary for the disease to emerge.
If you are concerned about the possibility of a family history of MND and what that could mean for those close to you (in terms of inheriting the genetic code), you may wish to seek genetic counselling. Although sensitive to the emotional aspects of the situation, genetic counselling is not a form of psychotherapy. A genetic counsellor explains the facts as clearly as possible, and gives you accurate information on the implications for your family.
This will include information about options such as genetic testing, to help you make up your own mind if this is a choice you wish to make. Some genetic testing is possible, but not everyone with a family history would benefit. Currently, testing is only available for four of the genes that play a part in inherited MND and results are not necessarily conclusive.
Choosing to be tested can be a very difficult decision, as it affects the wider family. We would advise genetic counselling from a neurological expert experienced in MND. In the first instance talk to your neurological consultant for advice.
There has been an acceleration of world-wide research into the disease and its causes, including projects funded by the MND Association. As a result, our understanding of MND and the way motor neurones function is constantly advancing.
You can read more about MND where there is a family history in Research Information Sheet B – Inherited MND part one: Introduction to inherited MND (183 kb)