A genetic mutation that confers a 70 percent chance of developing multiple sclerosis could point the way for new therapies. The ultimate cause for the disorder, during which the protective layers of myelin surrounding nerve fibres are degraded by the body’s immune system, has remained a mystery to researchers for decades. 

Scientists from the University of British Columbia studied the DNA of hundreds of families affected by MS, finding two families and 11 individuals (seven with MS) who carried the mutation. Further studies in mice demonstrated that knocking out the function of the same gene, NR1H3, caused neurological problems and decreased myelin production. 

The mutation in NR1H3 – a simple one-letter type that completely alters the protein made by the gene – only occurs in 1 in 1,000 people with MS, leading some scientists to dispute how relevant this discovery will be for most patients. 

“I would be very surprised if it turns out to be true,” said Dr. Nikolaos Patsopoulos, a neurologist and MS geneticist at Brigham and Women’s Hospital in Boston, speaking to STAT.

NR1H3 also has a role to play in the metabolism of blood lipids, like triglycerides and cholesterol, prime targets for current drug development. As a result, lead researcher Dr Carles Vilarino-Guell is optimistic that existing potential drugs could be re purposed and developed for MS therapy.

“These are still early days and there is a lot to test,” said Dr Vilarino-Guell. “But if we are able to repurpose some of these experimental drugs, it could shorten the time it takes to develop targeted MS treatments.”