syndromic disease muscle tissue disorder myalgic encephalomeyelitis/chronic fatigue syndrome myalgic encephalomyelitis MEDGEN:5130 Orphanet:1983 chronic fatigue immune dysfunction syndrome CFS SCTID:51771007 DOID:8544 ICD9:780.79 UMLS:C0015674 systemic exertion intolerance disease MESH:D015673 myalgic encephalitis ICD9:780.71 chronic fatigue syndrome Postviral fatigue syndrome EFO:0004540 NCIT:C3037 A medical condition characterized by long-term fatigue and other symptoms that limit a person's ability to carry out ordinary daily activities. immunodeficiency disease hereditary neurological disease