Multiple sclerosis has been linked to more than two dozen new genetic variants that could help guide the search for treatments, researchers say.
Many of the genes implicated play key roles in how the immune system works, an international team of researchers reported in Thursday's issue of the journal Nature. A second study that confirms the findings appeared in the journal PloS Genetics at the same time.
To identify the 29 new genetic variants, researchers studied the DNA of more than 9,000 individuals with multiple sclerosis and more than 17,000 unrelated healthy controls.
The findings endorse current treatments offered by neurologists, said Dr. Alastair Compston, a senior author of the work and a neurology professor at the University of Cambridge.
"It is very clear to us from this study that the tactic of trying to deal with the inflammatory response early is the right tactic," Compston said.
These data confirmed a link between MS and a large genetic region called the major histocompatibility complex (MHC), which plays a role in the immune system and autoimmunity.
"Hope always has to depend on hard fact and truth — this provides some definite hard facts about the cause of MS," clinical immunologist and Prof. Graeme Stewart at the University of Sydney, told the Australian Broadcasting Corporation.
"It won't produce an answer tomorrow or in the next two or three years, but it will set the world off to get an understanding of the cause, and it's the understanding of the cause that leads on to the cure," added Stewart, who led the Australian and New Zealand contribution to the research.
The PLoS research paper found that nearly half of the 107 genetic variants previously linked to an autoimmune disease are also found in at least one other autoimmune disease, such as MS, Crohn's disease, psoriasis, rheumatoid arthritis, lupus, celiac disease and Type 1 diabetes.
Blocked-vein theory not addressed
Italian doctor Paolo Zamboni's controversial theory points to blocked veins as contributing to MS and that unblocking them can help relieve symptoms.
"The work was not designed in any way to address ideas that Dr. Zamboni has put forward, but in my opinion, it contributes nothing to that debate," Compston said.
After living with MS for 13 years, Debbie Patterson of Winnipeg fundraised $13,000 and travelled to Costa Rica for the vein treatment.
"I wonder what that neurologist thinks of the thousands of people who have shown measurable improvements since having the therapy," said Patterson.
Patterson said she can walk better, snap her fingers for the first time in years, and pick up items off the floor. She said her recent neurological tests also show her condition has improved since she had the vein treatment in January.
Patterson considered the genetic findings significant, but said they take nothing away from the benefits she has felt.
Newfoundland and Labrador, Saskatchewan and Manitoba as well as the federal government have also committed to clinical trials to assess vein opening.
"Is the so-called liberation therapy an actual meaningful intervention for people living with MS that can alleviate their symptoms, take away some of their discomfort and give them quality of life?" Manitoba Health Minister Teresa Oswald said in explaining the province is going ahead with its plans.
The U.S. National Institutes of Neurological Disorders and Stroke of the U.S. National Institutes of Health and the National Multiple Sclerosis Society funded both studies.