After decades of failed attempts, two new genetic variants have been identified that increase the risk of developing multiple sclerosis. Given that the long-known risk factor HLA-DRB1 accounts for “less than half of the total genetic basis for the disease,” the recent finding represents “a welcome breakthrough”, said Lee Dunster of the Multiple Sclerosis Society ( The Times , 30 July 2007).

Genome-wide analysis, reported in The New England Journal of Medicine (29 July 2007), revealed that the two variants — in the genes encoding interleukin-7 receptor α-chain (IL-7Rα) and IL-2Rα — increased the risk of developing the disease by up to 30%. Two further independent studies, published in Nature Genetics (29 July 2007), confirmed the disease association with IL-7Rα and showed that this variant had an effect on gene function. However, one author cautioned that, “A lot of people carry this particular variant, and they don't get multiple sclerosis” ( Nature News , 29 July 2007), so many more genes are probably involved.

Because IL-2Rα has also been linked to type 1 diabetes and autoimmune thyroid disease, “this study will likely spur further research into the connection between these seemingly separate conditions”, predicts David Hafler, a primary author of one of the studies ( The Independent , 30 July 2007). The interaction between IL-7Rα and regulatory T cells will also be a major focus of research, said another author, Stephen Hauser (The Times, 30 July 2007).

Hopes of a vaccine for treating multiple sclerosis have also been raised recently. In the Archives of Neurology, Amit Bar-Or and colleagues report the results of a small DNA vaccine trial in patients with multiple sclerosis, indicating that it “was safe and well tolerated, provided favourable trends on brain MRI and produced beneficial immune changes.” ( Telegraph , 14 August 2007.)