Researchers have discovered the first genetic marker associated with a faster progression of multiple sclerosis (MS), paving the way for new treatments to be developed for the lifelong condition.
The global study of more than 22,000 people with MS involved 70 global institutions led by scientists from the University of Cambridge and the University of California San Francisco (UCSF) in the US.
The immune system of people with MS attacks their brain and spinal cord, resulting in symptoms such as fatigue and problems with vision, movement, sensation and balance.
The degenerative condition can, in some cases, cause disability and reduce life expectancy.
While treatment has been developed to tackle symptoms, none can prevent its progression.
Understanding how the variant exerts its effects on MS severity will hopefully pave the way to a new generation of treatments that are able to prevent disease progression— Professor Stephen Sawcer
Looking at statistics from The International Multiple Sclerosis Genetics Consortium (IMSGC) and The MultipleMS Consortium, researchers assessed genetic factors influencing MS severity.
They combined data from 12,584 people with MS, linking genetic variants to particular traits such as the time it took for each individual to advance from diagnosis to a certain level of disability.
After sifting through 7.8 million genetic variants, one was found to be associated with faster disease progression.
The variant sites between two genes with no prior connection to MS, known as DYSF and ZNF638. The first repairs damaged cells and the second helps control viral infections.
Professor Sergio Baranzini at UCSF, who is co-senior author of the study which has been published in Nature, said: “Inheriting this genetic variant from both parents accelerates the time to needing a walking aid by almost four years.”
Dr Adil Harroud, lead author of the study and former postdoctoral researcher in the Baranzini Lab at UCSF, added: “These genes are normally active within the brain and spinal cord, rather than the immune system.
“Our findings suggest that resilience and repair in the nervous system determine the course of MS progression and that we should focus on these parts of human biology for better therapies.”
To confirm their findings, the research team looked as the genetics of an additional 9,805 people and found those with two copies of the variant became disabled faster.
Professor Stephen Sawcer from the University of Cambridge and Cambridge University Hospitals NHS Foundation Trust, said: “Understanding how the variant exerts its effects on MS severity will hopefully pave the way to a new generation of treatments that are able to prevent disease progression.”
He added: “Although it seems obvious that your brain’s resilience to injury would determine the severity of a disease like MS, this new study has pointed us towards the key processes that underlie this resilience.”
The research team is now collecting a larger set of DNA samples from people with MS to find other variants that could contribute to disability from the condition.
