SNPwatch: New Associations Found for Multiple Sclerosis

Editor’s note: Pending an FDA decision, 23andMe no longer offers new customers access to health reports referred to in this post. Customers who purchased prior to November 22, 2013 will still be able to see their health reports, but those who purchased after that time will not. Those customers will have access to ancestry information as well as access to their uninterpreted raw data.

Scientists know that there isn’t one cause for multiple sclerosis (MS), but understanding this complex autoimmune disease has vexed medical researchers for years.

In the largest MS study to date, researchers recently identified 29 new genetic variants associated with the disease in people of European descent, bringing the list of MS-related genetic factors to more than 50.

The work, led by scientists at the Universities of Cambridge and Oxford and funded by the Wellcome Trust, also sheds more light on the molecular biology of the disease. Most of the variants discovered are in or near genes that drive the body’s immune responses, specifically those involved in the production of T-cells.

Multiple sclerosis is an autoimmune disease in which a person’s immune system attacks the myelin sheath that insulates nerve fibers in the brain and spinal cord. The damage to the sheaths impairs the signals traveling along the nerves, which in turn causes a range of symptoms including weakness, sensory disturbance, fatigue, visual impairments and loss of coordination. About 2.5 million people suffer worldwide from MS with about 400,000 of those in the United States.

“Our research settles a longstanding debate on what happens first in the complex sequence of events that leads to disability in multiple sclerosis,” said Alastair Compston, of the University of Cambridge, who led the study with Peter Donnelly from the Wellcome Trust Center for Human Genetics on behalf of the International Multiple Sclerosis Genetics Consortium.

“It is now clear that multiple sclerosis is primarily an immunological disease,” Compston said in a press release in early August.

(23andMe customers can look up 10 of the strongest associations newly identified in the study in their accounts using the Browse Raw Data feature and the table at the end of this post.)

What is also interesting about this latest research is that many of the genetic factors involved in MS are shared with other autoimmune diseases, like Crohn’s disease, lupus and type 1 diabetes.

One of the authors of the study, Dr. David Hafler, a professor of neurology and immunobiology at Yale University, said the breakthrough goes beyond just research into MS, but may help researchers in finding new ways to fight both MS and other diseases.

While researchers know that genetic plays an important role — people of European ancestry are more susceptible and a family history of MS also increases the odds of developing the disease — it’s only one of a large combination of factors that include environmental factors such as vitamin D intake, smoking, exposure to toxic chemicals and things like whether someone has had certain viruses like Epstein-Barr. In short multiple sclerosis is unpredictable and complex.

The new study involved nearly 10,000 people with MS from 15 different countries and a group of more than 17,000 people without the disease. In all, 23 research groups collaborated on the research.

Novel genetic associations for multiple sclerosis*

Variant Nearest Gene Version Odds Ratio
TAGAP T 0.88
None C 1.15
TNFSF14 T 0.88
IL22RA2 G 1.14
MYB A 1.09
ZFP36L1 T 0.88
PLEK G 0.87
CYP24A1 T 0.90
IL12B G 0.87
CD86 A 0.83

* Associations applicable in populations with European ancestry

SNPwatch gives you the latest news about research linking various traits and conditions to individual genetic variations. These studies are exciting because they offer a glimpse into how genetics may affect our bodies and health; but in most cases, more work is needed before this research can provide information of value to individuals. For that reason it is important to remember that like all information we provide, the studies we describe in SNPwatch are for research and educational purposes only. SNPwatch is not intended to be a substitute for professional medical advice; you should always seek the advice of your physician or other appropriate healthcare professional with any questions you may have regarding diagnosis, cure, treatment or prevention of any disease or other medical condition.