Newly discovered and rare genetic variations account for a small but important proportion of inherited multiple sclerosis (MS) risk, a new study reports. The newly discovered genetic variations all appear to affect the immune system.
In the study titled: “Low-Frequency and Rare-Coding Variation Contributes to Multiple Sclerosis Risk,” published in the journal Cell, the genetic profiles of 68,000 people, about half of whom have MS, were studied.
Led by scientists at Yale University, a team from the International Multiple Sclerosis Genetics Consortium (IMSGC), studied mutations which appear infrequently in the population rather than looking at common genetic variants.
“We simply would not have found these rare genetic mutations by continuing to look at common genetic variants; we had to look for rarer events, which meant looking at many, many more people,” Chris Cotsapas, an associate professor of neurology and genetics at Yale and senior author of the study, said in a news release. The new variants, identified in four genes, drive either a higher or a lower susceptibility to MS, independently of other common variants already known.
Overall, the discovery of these low-frequency genetic variants “constitute a rich resource for dissecting the pathobiology [the biological mechanism] of MS,” the researchers wrote.
The newly discovered variants are present in genes which “have clear immunological functions, confirming that MS pathogenesis is primarily driven by immune dysfunction,” they added.
Source: MS-UK 24/10/2018