New blood test for familial motor neurone disease to be developed

An international team of scientists has identified a genetic defect responsible for familial motor neurone disease (MND). A region on chromosome 9 was found to be expanded in 40 percent of people with familial MND. It is hoped that a blood test for this disease will be available on the NHS in the near future.

'Chromosome 9 has been a prime suspect in motor neurone disease for some time, but pinning down the precise genetic factor involved had proved elusive', said Dr Brian Dickie, director of research development at the Motor Neurone Disease Association, who was not involved in the study. 'The discovery of this rogue gene has the potential to significantly advance our understanding of motor neurone disease, helping scientists to home in on the pivotal cellular changes underlying all forms of the disease'.

Researchers from the UK, the USA, Finland and the Netherlands analysed the DNA of a large group of familial MND patients in Finland and a single family in the UK. They identified a region of DNA on chromosome 9, within the C9ORF72 gene, which was significantly expanded in familial MND patients. Healthy individuals have five to ten copies of this stretch of DNA, while those with the disease were found to have thousands of copies.

This genetic defect is similar to that found in the related muscular disease myotonic dystrophy, for which there is already a test.

'There's an NHS blood test for that [myotonic dystrophy], so this should be reasonably straightforward. Certainly, there should be a blood test available within a few months', said co-author Dr Huw Morris of the University of Cardiff. 'The NHS laboratory in Cardiff that we worked with is working on it now'.

MND is characterised by the wasting away of muscle, resulting from the degeneration of the nerves that connect to these muscles and control their movement, namely motor neurones. Disease progression results in increased difficulty in walking, breathing and swallowing, and ultimately leads to paralysis and death. Approximately 1 in every 50,000 people in England are affected by the disease, with ten percent displaying a family history and therefore presenting with familial MND.

There is currently no cure for motor neurone disease, with approximately half of patients dying within 14 months of diagnosis. The development of this test would allow patients to determine whether or not their disease due to an inherited genetic defect, or to find out if they are at risk if they believe they could have inherited the disease.

This study was published in the journal Neuron.