THURSDAY, April 20 (HealthDay News) — U.S. scientists have identified certain genetic traits common to people who suffer from chronic fatigue syndrome (CFS), strongly suggesting a genetic basis for the condition.

The genetic make-up identified by the researchers involves the body’s ability to adapt to change and to withstand common life stresses such as injuries and infections.

“This really is the first credible evidence of a biological basis for chronic fatigue syndrome,” Dr. Julie Gerberding, director of the U.S. Centers for Disease Control and Prevention, said at a Thursday press conference. “It reflects the remarkable confluence of a number of scientific advances that are coming to bear on a problem of great importance to many people in the U.S. It’s an important step forward in the field of chronic fatigue syndrome research.”

The information should one day translate into better ways to diagnose and treat chronic fatigue syndrome, added Dr. William Reeves, the CDC’s lead CFS scientist, at the same conference.

Outside experts noted that this research really builds on other findings over the last decade, which had already uncovered evidence of physiological markers for CFS.

“Over the last decade, there have been a number of investigators who have found some very intriguing things,” said Leonard Jason, professor of psychology at DePaul University in Chicago and director of DePaul’s Center for Community Research. “The problem is they don’t occur in 100 percent of cases. We’ve got many different subsets and we need to start looking at these groups that have different biological aberrant patterns.”

More than one million people in the United States are estimated to suffer from CFS, costing the nation some $9 billion annually, and each family $20,000 per year in lost earnings. The condition is more common in women aged 40 to 60 and is marked by a cluster of debilitating symptoms, including unexplained fatigue, problems sleeping, problems with memory and concentration, and pain. CFS can be as disabling as multiple sclerosis.

The illness was first recognized in the late 1980s and, initially dubbed the “yuppie flu,” suffered from a credibility crisis. “One of the common stereotypes is that this is a bunch of hysterical, upper-class, professional, white women,” Reeves said.

The condition remains a mysterious one. “Despite more than two decades of basic and clinical research and at least 3,000 peer-reviewed papers, we’re still learning a lot about it,” said Reeves.

The CDC findings appear in a series of 14 research papers released Thursday by the agency and published in the April issue of Pharmacogenomics.

The research, called the CFS Computational Challenge, or C3, involved a group of 227 people with chronic fatigue syndrome in Wichita, Kan. Participants spent two days in a hospital research ward undergoing extensive tests, including clinical evaluations, measurements of sleep physiology, cognitive function (memory and concentration), autonomic nervous system function, and blood evaluations that featured an investigation of the activity of 20,000 genes.

Four different teams comprised of scientists from a number of different disciplines then looked at the data independently.

The teams found that “people with CFS have certain genes that are related to those parts of the brain activity that mediate stress response, and they have different gene activity levels,” Reeves said. “This is related to the body’s ability to adapt to challenges and stresses that occur through life such as injury and trauma.”

Dr. seo services Suzanne Vernon, the molecular epidemiology team leader for the CFS Research Laboratory at the CDC, added: “There are differences in the actual genetic make-up, in the DNA code, that probably results in differ