A 30-year-old man developed unexplained rhabdomyolysis, persistently increased creatine kinase and severe debilitating muscle cramps. After a nondiagnostic neurologic evaluation, he was referred for a muscle biopsy, to include histology/histochemistry, a myoglobinuria panel, and a caffeine halothane contracture test. Only the caffeine halothane contracture test was positive, and a subsequent ryanodine receptor type 1 gene evaluation revealed a mutation functionally causative for malignant hyperthermia. His identical twin brother, who was suffering from similar complaints, was found to share the same mutation. They each require oral dantrolene therapy to control symptoms, despite difficulty in identifying health care providers familiar with treating this disorder.
From the *Department of Anesthesiology, Walter Reed National Military Medical Center, Bethesda; †DVCIPM, Rockville; ‡Department of Anesthesiology, Uniformed Services University of the Health Sciences; Departments of §Neurosurgery and ‖Neurology, Walter Reed National Military Medical Center, Bethesda, Maryland; ¶Department of Military Medicine, Uniformed Services University of the Health Sciences; and **Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas.
Accepted for publication February 28, 2014.
Funding: Department of Defense grant W81XWH-10-2-0117.
This report was previously presented, in part, at the MHAUS Meeting, Toronto, Canada.
The authors declare no conflicts of interest.
Address correspondence to John F. Capacchione, MD, Department of Anesthesiology, Uniformed Services University of the Health Sciences, USUHS/4301 Jones Bridge Rd., Bethesda, MD 20814. Address e-mail to firstname.lastname@example.org.