December 29, 2003
A slight genetic variation appears to be a big risk factor for multiple sclerosis.
People carrying two copies of the variant, in gene CD24, are significantly more likely to develop multiple sclerosis, according to research led by Yang Liu of Ohio State University in Columbus.
They also progress from first symptom to severe walking difficulties eight years sooner than people with one or no copies of the variant.
Runs in the family
Multiple sclerosis is an autoimmune disorder of the central nervous system in which nerve function is affected by the loss of an insulating sheath called myelin.
While the disease's underlying cause isn't known, researchers think that genes play a big role. It is more common in family members of people with the condition than in the general population.
For their study, Liu and colleagues examined 242 people with multiple sclerosis and 207 healthy controls.
They suspected that CD24 conferred risk because the gene is associated with the disease in mice.
They found that a small change of just one single nucleotide polymorphism in CD24—a single DNA "letter"—was associated with increased risk.
The researchers aren't recommending that people be tested for the variant yet, however. They now aim to better understand the gene's role.
Their study is reported in the Proceedings of the National Academy of
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