The study was small—involving just 40 patients—but the results couldn't have been better. Researchers were able to correctly determine which 20 of those patients suffered from chronic fatigue syndrome based on a blood test, reports the San Jose Mercury News. A larger, more robust test is now in the works, and if the results hold up, it could prove to be a breakthrough for the vexing disorder known more formally as myalgic encephalomyelitis. "This could be a transformative advance," a genetics professor at UC San Diego not involved with the Stanford study tells the San Francisco Chronicle. Essentially, the researchers may have discovered a "biomarker" that could greatly improve diagnosis. What's more, the existence of such a biomarker could lay to rest any speculation that the disease isn't really a disease.
"There are physicians around who say if there is no biomarker the disease doesn't exist, as far as they're concerned," says lead researcher Ron Davis. "I'm hoping this will help the medical community accept that this is a real disease." Davis and his team used a tool called a nanoelectronic assay to analyze blood samples and measure small changes of energy within them. They discovered telltale spikes in those with CFS, but whether this amounts to a definitive biomarker remains the key question. NBC News talks to a specialist in Australia who cautions that it's "very premature" to declare success given how small the study was. CFS can cause crippling joint pain, headaches, and fatigue, and an estimated 2.5 million have it in the US. (One of the most well-known sufferers is Laura Hillenbrand, author of Seabiscuit and Unbroken.)