Genetic Clue for Managing Multiple Sclerosis

October 1, 2007
Breakdown: cross section of human nerve highlighting myelin sheath, which is attacked during MS

Breakdown: cross section of human nerve highlighting myelin sheath, which is attacked during MS

 

A newly identified gene may help guide future research into therapies for multiple sclerosis. Researchers say their identification is the first major genetic advance in thirty years toward understanding this nervous-system disease.

While it has been known that there is a strong genetic underpinning for multiple sclerosis, until now, only genes within a region of Chromosome 6 have been implicated in the disease. The current finding, reported in the journal Nature Genetics, demonstrated that a functional gene variant on Chromosome 5 was associated with an increased susceptibility to the disease.

"Our finding is very important because the genetic factors that are already known to be associated with multiple sclerosis only explain less than half of the total genetic basis for the disease," says Simon Gregory, the paper's first author and an assistant professor in Duke's Center for Human Genetics. "We have identified a gene that increases an individual's risk of MS by 30 percent and that this variant has an effect on the function of the gene."

Gregory's research team, which included researchers at Duke, the University of California at San Francisco, the University of Cambridge, the University of Miami, and Vanderbilt University, also published a paper in the New England Journal of Medicine replicating similar findings.

Multiple sclerosis is a disease that is caused by the breakdown of the fatty sheath surrounding axons, the long spindly portions of nerve cells that carry messages from one cell to another. This sheath, known as myelin, acts much like the plastic coating insulating an electrical cord.

For reasons that are not well understood, the body's own immune system is believed to attack the myelin, which can cause "short circuits" in the body's electrical system. What triggers this autoimmune response is likely a result of a complex interplay between genetic and environmental factors, Gregory says.