A group of international researchers has identified 48 new genetic variants that influence the risk of developing multiple sclerosis (MS). This brings the number of genetic 'risk factors' linked to the disease to 110.
The study, published in the journal Nature Genetics, examined DNA samples from around 80,000 people with and without MS. It is thought to be the largest investigation of multiple sclerosis genetics yet performed and involved 193 scientists from 84 research groups in 13 different countries.
One of the leading scientists on the project, Dr David Booth from the University of Sydney, commented: 'Every one of those new genes is potentially providing us with a new way to understand the disease and to come up with new therapies for the disease'.
In MS, the coating around nerve fibres, called myelin, is damaged as the immune system mistakes myelin for a foreign body and attacks it. Depending on where in the central nervous system the damage occurs, this can cause problems with mobility, balance, sensation and cognition. MS is normally diagnosed in people between the ages of 20 and 40 and is a lifelong, degenerative illness. Around 2.5 million people worldwide are thought to be affected. Treatments exist, but a cure remains elusive.
The genes implicated in this study underline the central role the immune system plays in the disease and show some overlap with other autoimmune diseases, like inflammatory bowel disease and coeliac disease.
Dr Booth said that the researchers would now look at 'which processes are tagged by groups of genes and that will give us specific information on immune processes that are not functioning as they should'.
Dr Susan Kohlhaas, head of biomedical research at the MS Society in the UK, which co-funded the study, said: 'We need to discover as much as we can about the factors that may increase a person's risk of developing MS if we're to find new ways of treating or even, one day, preventing the condition. Genes are one of the key risk factors, so we're delighted to have co-funded this work, which has identified several new avenues for MS research to follow'.