| Motor neurone disease culprit identified|
|A new gene variant believed responsible for hereditary cases of motor neurone disease has been discovered by an international team of scientists.|
The study, reported today in the journal Science, found mutations in a gene called FUS (fused in scarcoma) cause the build-up of toxic proteins that eventually kill nerve cells, causing motor neurone disease (MND).
The researchers hope the discovery will shed light on how the condition develops and pave the way for treatments to prevent the accumulation of the toxic proteins.
Every day at least one Australian is diagnosed and another is killed by MND, a progressive, neurological disorder caused by degeneration of motor neurones.
Motor neurones control voluntary muscle movement and MND kills nerves to all muscles, affecting a person's ability to move, breathe and swallow.
Professor Garth Nicholson, of the University of Sydney and colleagues in the US and UK found 15 mutations in FUS genes found in hundreds of patients with hereditary or familial MND.
Hereditary MND runs in families and is responsible for 10% of cases.
The mutations cause a protein, normally contained in the nucleus of nerve cells, to accumulate in the fluid outside the nucleus and this kills the cells.
"When this protein accumulates it's toxic and causes disease," says Nicholson.
Nicholson says the protein produced by the abnormal FUS gene appears related to another protein, called TDP-43.
TDP-43 protein also slowly accumulates in motor neurones and is present in 90% of all people with MND.
Nicholson and colleagues last year identified an Australian family and a British relative with TDP-43 protein in dying motor neurones.
In this study, Nicholson and colleagues found families suffering MND with the FUS gene in diseased neurones
This is the first time a common cause of nerve cell death in MND has been discovered.
Nicholson says at this stage the FUS gene appears only in familial MND cases but it could be part of a common mechanism underlying the disorder because it is the second protein implicated.
He says the eventual aim is to find drugs which can prevent the pile-up of toxic protein.
MND families push for research
Searching for the cause of inherited MND began in the 1980s after a family in Newcastle, Australia, convinced Nicholson and other doctors it could be hereditary.
Newcastle IT worker Darryl Preston says his father Wal began trying to convince doctors who didn't believe MND could be hereditary after his mother Janice was diagnosed.
"Dad was a sheet metal worker who pushed the barrow to try to save his wife and sons," says Darryl. "He told doctors 40 members of her family had suffered MND, going as far back as 150 years to when it was called 'creeping paralysis'."
"My family set about trying to find doctors here and overseas to prove it was hereditary. Professor Nicholson started taking blood and samples from our family and looking for answers and we travelled the world including to the US, taking 35 blood samples with us."
Darryl says he is excited by the new findings.
"Let's step up research and stop this shocking disease," he says.
Nicholson's group is looking for more MND families to help with the research.
MND affects about 1300 people in Australia, according to MND Australia.
Also known as Amyotrophic Lateral Sclerosis (ALS) in some parts of the world, and in the US as Lou Gehrig's disease after a baseball star, the best known living patient with MND is UK physicist Professor Stephen Hawking.