The largest-ever genetic study of multiple sclerosis has revealed dozens of new genetic markers associated with the disease, according to a presentation to the American Society of Human Genetics by a Greek researcher.

The findings, which are to be made available to researchers all over the world, will jumpstart research on the specific genes implicated in the neurodegenerative disease, according to Nikolaos Patsopoulos, a professor at Harvard Medical School and principal investigator.

Researchers now have a common map of 200 locations where they can look for clues to the causes of MS.

“We now know there are many, many more loci associated with the disease, more than double. We can now provide researchers with a very extensive list of prioritized genes that they can investigate.”

Patsopoulos presented the findings of the International Multiple Sclerosis Genetics Consortium at the American Society of Human Genetics 2016 annual meeting in Vancouver. To tease out the genetic variations related to the disease, consortium researchers at 30 institutions in 18 countries compared the DNA of 47,351 people with MS and 68,284 people without the disease.

“New locations on the X chromosome are very exciting because MS is twice as common in women than it is in men,” said Patsopoulos.

The immune systems of people with MS attack the insulating myelin coating on nerve cells in the brain and spinal cord, leading to muscle weakness, brain damage, blindness and other physical and mental symptoms.

The disease appears to be triggered by a mysterious interaction between lifestyle factors and genetic susceptibility, which has long frustrated scientists. Patsopoulos hopes the consortium’s findings will help the research community shine some light in that black box.

“Given how complex the environment is and how everyone’s life is so different, the one thing that doesn’t change is your DNA,” he said. “It’s the only stable part of a very complex system, so it provides the best opportunity to explain the disease.”

Most of the newly identified variants are specific to the function of immune cells and just a few that might be related to brain function, which helps point MS researchers in the right direction.

“Just as important, we have proven that many other locations in the genome have nothing to do with the disease, that there is nothing there to find,” said Patsopoulos.

He expects the list of genetic locations associated with MS will continue to grow — possibly as high as 300 — as more people’s genetic data becomes available to the project.

Many of the genes identified in the study are also involved in other autoimmune diseases, including rheumatoid arthritis and ulcerative colitis, and may affect the same immune system cells, but in different ways.

“This confirms the complex interplay of different elements of the immune system in MS susceptibility and highlights the role of several different immune cells that contribute to the initiation of this inflammatory disease,” explained Phil De Jager, senior author of the study.

Nikolaos A. Patsopoulos, MD, PhD, a principal investigator in the Ann Romney Center for Neurologic Diseases at Brigham and Women’s Hospital (BWH), assistant professor of Neurology at Harvard Medical School, and associate member at the Broad Institute.