Functional properties of RYR1 mutations identified in Swedish patients with malignant hyperthermia and central core disease.

Background: A diagnosis of malignant hyperthermia susceptibility by in vitro contraction testing can often only be performed at specialized laboratories far away from where patients live. Therefore, we have designed a protocol for genetic screening of the RYR1-cDNA and for functional testing of newly identified ryanodine receptor 1 (RYR1) gene variants in B lymphocytes isolated from peripheral blood samples drawn at local primary care centers.

Methods: B lymphocytes were isolated for the extraction of RYR1-mRNA and genomic DNA and for establishment of lymphoblastoid B cell lines in 5 patients carrying yet unclassified mutations in the RYR1.

Mutation screening of the RYR1-cDNA from peripheral B-lymphocytes in 15 Swedish malignant hyperthermia index cases.

Background: Malignant hyperthermia (MH), linked to the ryanodine receptor 1 gene (RYR1) on chromosome 19, is a potentially lethal pharmacogenetic disorder which may lead to a disturbance of intracellular calcium homeostasis when susceptible individuals are exposed to halogenated anaesthetics, suxamethonium, or both. Central core disease (CCD) is a rare dominantly inherited congenital myopathy allelic to MH-susceptibility.

Methods: In this study, 14 unrelated MH-susceptible probands and one CCD patient from Sweden were screened for mutations in the RYR1.

Malignant hyperthermia and central core disease causative mutations in Swedish patients.

Background: Malignant hyperthermia (MH) susceptibility is a pharmacogenetic disorder of intracellular calcium homeostasis. In susceptible individuals, halogenated anaesthetics and/or suxamethonium may trigger an MH reaction. The diagnosis of MH susceptibility is made by an in vitro contracture test of biopsied muscle strips.