Scientists have identified 48 new genetic variants that influence the risk of developing multiple sclerosis, a disabling neurological condition.
The work by scientists from the International Multiple Sclerosis Genetics Consortium (IMSGC) nearly doubles the number of known genetic risk factors for the condition.
The genes implicated by the newly identified associations underline the central role played by the immune system in the development of multiple sclerosis and show substantial overlap with genes known to be involved in other autoimmune diseases.
Led by the University of Miami Miller School of Medicine's Jacob McCauley, on behalf of the IMSGC, the study relied upon an international team of 193 investigators from 84 research groups in 13 countries.
Multiple sclerosis (MS) affects over 2.5 million individuals worldwide. The disease results in patchy inflammation and damage to the central nervous system that causes problems with mobility, balance, sensation and cognition depending upon where the damage to the central nervous system occurs.
The present study takes advantage of custom designed technology known as ImmunoChip - a high-throughput genotyping array specifically designed to interrogate a targeted set of genetic variants linked to one or more autoimmune diseases.
IMSGC researchers used the ImmunoChip platform to analyse the DNA from 29,300 individuals with multiple sclerosis and 50,794 unrelated healthy controls, making this the largest genetics study ever performed for multiple sclerosis.
In addition to identifying 48 new susceptibility variants, the study also confirmed and further refined a similar number of previously identified genetic associations. With these new findings, there are now 110 genetic variants associated with MS.
Although each of these variants individually confers only a very small risk of developing multiple sclerosis, collectively they explain approximately 20 per cent of the genetic component of the disease.
"By further refining the genetic landscape of multiple sclerosis and identifying novel genetic associations, we are closer to being able to identify the cellular and molecular processes responsible for MS and therefore the specific biological targets for future drug treatment strategies," McCauley said.
The study was published in the journal Nature Genetics.