Nobody knows the precise cause of Motor Neurone Disease and researchers are currently looking at a number of possibilities. The Motor Neurone Disease
Association lists the following as possible causes of MND-
- Genetic abnormalities – The identification of a gene mutation has pinpointed the potential cause in the familial type of MND which affects
about 1 in 20 people with MND.
- Excitotoxicity, whereby excess glutamate (a single amino acid) becomes overactive in key areas of the brain and spinal cord and may cause
nerve damage.
- Excess oxidation – whereby the oxygen free radicals produced by our energy cells overproduce or are not “mopped up” effectively. Both motor
neurones and muscle cells have a high energy requirement.
- Viruses – infection by a “slow virus” which is contracted early in life but develops slowly so that the disease is only apparent later in life.This has
never been confirmed and there is very little evidence to support it.
With regard to familial MND, mutations of the gene SOD1 are known to be reponsible for 20% of cases. This gene codes for the enzyme superoside dismutase
which reduces the oxidative stress of cells in the body. It is thought that SOD1 mutations may increase the propensity for the enzymes to form protein
aggregates which are toxic to nerve cells.
