Hundreds of Genetic Variants for Multiple Sclerosis Identified

Scientists have defined 200 genetic loci that are common among patients with multiple sclerosis.

A study presented at the American Society of Human Genetics 2016 Annual Meeting included genomic data from 47,351 patients with multiple sclerosis, and 68,284 patients without the disease.

“This is the largest study of this disease worldwide," said principal investigator Nikolaos A. Patsopoulos, MD, PhD. “The large sample size provided the statistical power to pinpoint areas of the genome that are likely to be involved in MS, including less common genetic variants that tend to have a larger effect on disease.”

Through comparing genomes, the scientists were able to discover 200 genetic variants common among patients with multiple sclerosis (MS). The variants were associated with immune cells, and immune system function, as well as some that could be related to brain function.

“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,” said senior author of the study Phil De Jager, MD, PhD. “While we now have some hints, the mechanisms that lead this inflammatory disease to target the brain and spinal cord remain unclear.”

Many of the genetic variants were also associated with other autoimmune diseases, such as rheumatoid arthritis, type 1 diabetes, and ulcerative colitis. These findings raise questions about why these diseases have different clinical manifestations, according to the study.

“The differences and commonalities between MS and other autoimmune diseases are part of our line of research,” Dr Patsopoulos said. “Many of these conditions affect immune system cells, but we believe they change these cells in different ways, leading to different disease outcomes.”

The scientists stress that collaboration was extremely beneficial, and they would have likely been unable to complete this work on their own. The scientists who conducted the analysis are from the International Multiple Sclerosis Genetics Consortium (IMSGC), an organization that brings together researchers from 30 institutions to study multiple sclerosis.

“Only by sharing our energy and resources have we been able to produce this detailed genetic map of multiple sclerosis and to share this invaluable data with the rest of the MS research community,” said Adrian Ivinson, PhD, IMSGC coordinator. “Using the same approach, the IMSGC now hopes to turn its attention to the genetic underpinnings of progressive multiple sclerosis, the most aggressive form of MS.”