- The International MS Genetics Consortium (IMSGC) has published the largest MS genetics study to date, analyzing data from 47,429 people with MS and 68,374 individuals without MS.
- They confirmed 233 variations in the human genome that contribute to the risk of developing MS. The variations were found to influence many different immune cell types and tissues, indicating that broad dysfunction in the immune system underlies the onset of MS.
- The study also identifies a genetic variant for MS on chromosome X, the sex chromosome. Women have two X chromosomes while men have one; this is therefore an interesting lead to investigate why women are more likely to develop MS than men.
- These results alone are not sufficient to pinpoint who will develop MS, but they contribute to an understanding of risk factors that may eventually be used to predict an individual’s risk of developing MS and point to ways to prevent it.
- The IMSGC, a worldwide group of investigators collaborating to understand the genetic basis of MS, report this study in the magazine Science (365, eaav7188 [2019]).
“This study greatly expands our knowledge of the genetic variations that contribute to MS susceptibility, and establishes a roadmap to figure out what causes MS and how to prevent it,” said Bruce Bebo, PhD, Executive Vice President of Research at the Society. “This work would not be possible without the participation of people affected by MS, and the collective funding of agencies and MS Societies from around the world. It is an inspiring example of the collective power of patients, researchers, and funders coming together to accelerate vital research that brings us ever closer to a cure for MS,” he added. DETAILSBackground: The cause of MS is not yet known, but it is thought be triggered by a combination of factors in people whose genetic makeup (genome) make them susceptible. The International MS Genetics Consortium comprises the world’s top neurologists and geneticists. This team was supported with many sources including research grants from the National Institutes of Health and the National MS Society (in part through the generous support of Richard and Rosalyn Slifka) to undertake a search for MS genes throughout the human genome. They assembled data from multiple prior studies and then worked to confirm (replicate) those results in a large number of independent subjects, analyzing genetic data from a total of 115, 803 individuals. This replication effort was needed to increase confidence of previous findings. The Replication Study: In the largest MS genetic study to date, IMSGC researchers analyzed genetic data from 47,429 people with MS and 68,374 controls without MS. They confirmed 233 variations in the human genome that contribute to susceptibility to MS. These results confirm the initial results, representing a giant leap forward in understanding MS genetics.These results alone are not sufficient to pinpoint who will develop MS, but they contribute to an understanding of risk factors that may eventually be used to predict an individual’s risk of developing MS and point to ways to prevent it. The identified genetic variations influence the function of many immune cells types and tissues involved in initiating and carrying out immune attacks against the brain and spinal cord in MS. The team also found a link to the function of microglia, which are the immune cells of the brain, but not in other brain cells such as neurons or astrocytes. In addition, the study identified a genetic variation related to MS on chromosome X. Women have two X chromosomes (men have one), and this represents an intriguing lead to understanding part of the reason why women are more likely to develop MS than men. The IMSGC report this study in the magazine Science (365, eaav7188 [2019]).