Whites develop multiple sclerosis (MS)—a chronic and complex disease of the central nervous system—twice as often as blacks. But the disease also seems to affect each group differently in terms of its severity, symptoms and the time it strikes.

One study finding, published last year in an issue of the medical journal Neurology, showed that African-American MS patients had greater disease severity compared with white Americans suffering from the condition, even though those blacks had the illness for a shorter time.

What’s more, earlier study findings, published in a 2007 issue of the same journal, showed that blacks with MS experienced more difficulty walking than their white counterparts. In MS, recent genetic studies have begun to identify certain genes that are associated with MS.

According to John R. Rinker, MD, a member of the American Academy of Neurology and the earlier study’s lead author, there’s a possibility that these genes are unevenly distributed between ethnic groups, which might explain why different population groups are more susceptible to some diseases.

An even earlier study showed that doctors diagnosed blacks with MS at a later age than whites and with more diverse and severe symptoms.

But that race-related difference may also be because many black people tend to delay seeking medical attention until an illness is very advanced, says Carolyn Barley Britton, MD, MS, an associate professor of clinical neurology at New York City’s Columbia University Medical Center.

“Many people in our community are very drug-averse,” Britton says. “It’s a common scenario. People get evaluated much later and begin treatment when they are already [far] along in their disease process.”

All that said, and because MS has so many symptoms, the best bet is for people to get checked out when they develop any unusual signs that indicate something may be wrong. It’s always better to be safe than sorry, don’t you think?

(For more information about how multiple sclerosis affects different people, click here.)