The King syndrome: malignant hyperthermia, myopathy, and multiple anomalies.

Heterogeneity in malignant hyperthermia is being recognized with increasing frequency. In 1973, King described a subgroup of malignant hyperthermia patients with slowly progressive myopathy, short stature, kyphoscoliosis, pectus carinatum, cryptorchidism, and a characteristic facial appearance. Seven cases have been reported, all in males. We present the case of a girl with similar clinical findings who died in a malignant hyperthermia crisis and review the previously reported cases of King syndrome. The delineation of King syndrome provides further evidence for the heterogeneity of malignant hyperthermia and increases awareness of this disorder; its recognition in a female may lead to preoperative diagnosis and prevention of malignant hyperthermia crisis in King syndrome patients.