A case of minicore diseases (MCD) detected in a 10-year-old boy was reported and the nosological entity of this "myopathy" discussed. Its pathogenesis was unknown. Similar findings have been reported in many different conditions of human and experimental pathology. This suggests the possibility that at least some "core diseases" (central-, mini-, multicore myopathies), might not be diseases but just tissue syndromes. The possible relationship between these myopathies and malignant hyperthermia is stressed.