Illustration of nerve cells damaged by multiple sclerosis
Science Photo Library/Alamy
Researchers have identified the first genetic marker for the severity of multiple sclerosis. The genetic variant was seen in people who had a more rapid progression of the disease leading to greater disability. The discovery could lead to more effective treatments for the condition.
Multiple sclerosis is a chronic neurodegenerative disease that causes brain lesions and leads to difficulty with walking, memory and other bodily functions. It is not clear why some people with the condition can live relatively normal lives with treatment, while others experience rapid disease progression.
So, Adil Harrod at McGill University in Canada and colleagues performed a genome-wide association study using data from 22,389 people with multiple sclerosis. These types of studies use statistical analysis to determine genes associated with certain characteristics, such as the severity of multiple sclerosis.
After analyzing almost 8 million genetic variants, the researchers found one with a significant association with an age-adjusted outcome that measures disability in people with multiple sclerosis. On average, people with a marker need help walking 3.7 years earlier than those without it.
The team then examined brain tissue samples collected from a separate group of 290 people with multiple sclerosis who had died. On average, those with the marker had almost twice as many lesions in the outer layer of the brain and in their brainstem as those without without him. The researchers say this indicates that the variant has a link to the neurological damage that drives the progression of multiple sclerosis.
The finding could help clinicians identify which people with multiple sclerosis are more likely to have severe disease and adjust treatment plans accordingly, says Violin Harris at the Tisch MS Research Center in New York. “This new data can also help us understand and perhaps even segment patients when testing new treatment approaches,” she says.
One limitation of the study is that all participants were of European origin. The researchers were unable to replicate the findings in two cohorts of people of African and Hispanic descent. They say this may be due to the small sample size of these cohorts.
Topics: