Researchers have found that fibromyalgia is more common among the siblings, parents and children of those who have fibromyalgia than in the general population. But their research didn't clear up whether this phenomenon was the result of nature or nurture. A new study funded by the National Institutes of Health (NIH) will examine the role nature might play. Jane Olson, PhD, a genetic researcher at Case Western Reserve University in Cleveland, recently began a four-year, $2 million project to map genes in the selected relatives of 160 families with a history of fibromyalgia. "We're searching for genes that may cause fibromyalgia. If we find them, then we can learn about what's causing the syndrome on a biological level," says Olson. She expects those findings will help researchers develop effective treatments for fibromyalgia. In a previous study, Muhammad Yunus, MD, a rheumatologist at the University of Illinois College of Medicine in Peoria, found a link between fibromyalgia and a specific genetic marker by studying 40 families in which close relatives had fibromyalgia. That study was limited, however, because it only looked at one genetic marker present on the cells, notes Dr. Yunus, who will help conduct Dr. Olson's study as a co-investigator. Some researchers think psychological and social factors play a role in fibromyalgia because the syndrome has been found in people who have histories of physical and sexual abuse, alcoholism or depression in their families. To address these concerns, Olson plans to examine psychological and stress factors in her study, too. Whether there is a genetic cause of fibromyalgia has been a contentious topic for researchers to explore, notes David Sherry, MD, director of pediatric rheumatology at the Children's Hospital in Seattle. "Proving this is like proving the nature vs. nurture aspects of overweight children," he says. Families and doctors both hold strong opinions and it's easy to offend one side or the other. Plus, the criteria for diagnosing fibromyalgia tend to be subjective, and that makes it hard to research psychological or genetic factors in a statistical way, Dr. Sherry adds. Other researchers are examining familial tendencies toward pain syndromes in general, not just toward fibromyalgia. The NIH recently awarded Lesley Arnold, MD, a rheumatologist at the University of Cincinnati, a grant to study the prevalence of irritable bowel syndrome, migraines, chronic fatigue syndrome and mood disorders in the close relatives of people with fibromyalgia.