title: Malignant hyperthermia in a patient with Becker muscular dystrophy: dystrophin analysis and caffeine contracture study.
abstract: We present a 17-year-old boy with Becker muscular dystrophy (BMD) who developed hyperthermia and heart failure after general anesthesia. He presented clinical features of malignant hyperthermia (MH), and had masseter spasm and elevated body temperature (38.7 degrees C) with very high serum CK activity (107,000 IUl-1). Dystrophin tests confirmed a clinical diagnosis of BMD in the patient, i.e. faint and patchy immunostaining pattern of skeletal muscle, truncated dystrophin protein and a deletion of exons 3 and 4 of the dystrophin gene. To inquire into the mechanism of MH associated in the patient, we tested caffeine contracture reaction by the skinned fiber method. We found an increased sensitivity to caffeine only in type 1 muscle fibers. The rate of Ca(2+)-induced Ca2+ release (CICR) was normal, suggesting that the mechanism of "MH" observed in our patient with BMD is not the same as that of classical MH. A possible mechanism might be related to derangements of the sarcoplasmic reticulum membrane in BMD, which sensitize the membrane to caffeine or other agents.
authors.affiliation: Department of Neurology, University of Tsukuba, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Ohkoshi
authors.forename: T
authors.initials: T
authors.lastname: Yoshizawa
authors.forename: H
authors.initials: H
authors.lastname: Mizusawa
authors.forename: S
authors.initials: S
authors.lastname: Shoji
authors.forename: M
authors.initials: M
authors.lastname: Toyama
authors.forename: K
authors.initials: K
authors.lastname: Iida
authors.forename: Y
authors.initials: Y
authors.lastname: Sugishita
authors.forename: K
authors.initials: K
authors.lastname: Hamano
authors.forename: A
authors.initials: A
authors.lastname: Takagi
authors.forename: K
authors.initials: K
authors.lastname: Goto
mesh_terms: D000293:Adolescent; D000768:Anesthesia, General / Q000009:adverse effects; D015139:Blotting, Southern; D015153:Blotting, Western; D002110:Caffeine / Q000494:pharmacology; D002462:Cell Membrane; D016189:Dystrophin / Q000032:analysis / Q000235:genetics*; D006333:Heart Failure / Q000139:chemically induced / Q000150:complications; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008305:Malignant Hyperthermia / Q000209:etiology / Q000473:pathology*; D009132:Muscles / Q000737:chemistry / Q000187:drug effects / Q000473:pathology; D009136:Muscular Dystrophies / Q000473:pathology*
chemical_list: D016189:Dystrophin; D002110:Caffeine