BBC NEWS | Health | Chronic fatigue gene signs found: "Scientists believe they have pinpointed biological markers of chronic fatigue syndrome which could help develop a test and treatment for the condition.
CFS, or ME, makes people feel extremely tired, and can cause weakness, headaches, and disrupted sleep.
Dr Jonathan Kerr who led the research team, which is currently in the process of moving to St George's, said: "The involvement of such genes does seem to fit with the fact that these patients lack energy and suffer from fatigue."
He added the work could also potentially lead to a treatment for the condition.
"We have shown that a significant part of the pathogenesis resides in the white blood cells and in their activity
"It will open the door to development of pharmacological interventions."
Dr Russell Lane, a neurologist at Charing Cross Hospital, in London, said: "This exciting new work shows that some aspects of this complex illness may be understandable in molecular terms, and that CFS is not a 'made-up' illness."