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Janssens L, De Puydt J, Milazzo M, Symoens S, De Bleecker JL, Herdewyn S. Risk of malignant hyperthermia in patients carrying a variant in the skeletal muscle ryanodine receptor 1 gene. Neuromuscul Disord 2022; 32:864-869. [PMID: 36283893 DOI: 10.1016/j.nmd.2022.10.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 10/12/2022] [Accepted: 10/13/2022] [Indexed: 12/15/2022]
Abstract
Malignant hyperthermia is a life-threatening disorder, which can be prevented by avoiding certain anesthetic agents. Pathogenic variants in the skeletal muscle ryanodine receptor 1-gene are linked to malignant hyperthermia. We retrospectively studied 15 patients who presented to our clinic with symptoms of muscle dysfunction (weakness, myalgia or cramps) and were later found to have a variant in the skeletal muscle ryanodine receptor 1-gene. Symptoms, creatine kinase levels, electromyography, muscle biopsy and in vitro contracture test results were reviewed. Six out of the eleven patients, with a variant of unknown significance in the skeletal muscle ryanodine receptor 1-gene, had a positive in vitro contracture test, indicating malignant hyperthermia susceptibility. In one patient, with two variants of unknown significance, both variants were required to express the malignant hyperthermia-susceptibility trait. Neurologists should consider screening the skeletal muscle ryanodine receptor 1-gene in patients with myalgia or cramps, even when few to no abnormalities on ancillary testing.
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Affiliation(s)
- Lise Janssens
- Faculty of medical and health sciences, Ghent University, Corneel Heymanslaan 10, Ghent 9000, Belgium
| | - Joris De Puydt
- University Hospital of Antwerp, Drie Eikenstraat 655, Edegem 2650, Belgium; Faculty of medical and health sciences, Antwerp University, Prinsstraat 13, Antwerp 2000, Belgium
| | - Mauro Milazzo
- Center for Medical Genetics Ghent, Ghent University Hospital, Corneel Heymanslaan 10, Ghent 9000, Belgium
| | - Sofie Symoens
- Faculty of medical and health sciences, Ghent University, Corneel Heymanslaan 10, Ghent 9000, Belgium; Center for Medical Genetics Ghent, Ghent University Hospital, Corneel Heymanslaan 10, Ghent 9000, Belgium
| | - Jan L De Bleecker
- Faculty of medical and health sciences, Ghent University, Corneel Heymanslaan 10, Ghent 9000, Belgium; Department of Neurology, Ghent University Hospital, Corneel Heymanslaan 10, Ghent 9000, Belgium
| | - Sarah Herdewyn
- Department of Neurology, Ghent University Hospital, Corneel Heymanslaan 10, Ghent 9000, Belgium.
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Cotta A, Souza LS, Carvalho E, Feitosa LN, Cunha A, Navarro MM, Valicek J, Menezes MM, Neves SVN, Xavier-Neto R, Vargas AP, Takata RI, Paim JF, Vainzof M. Central Core Disease: Facial Weakness Differentiating Biallelic from Monoallelic Forms. Genes (Basel) 2022; 13:genes13050760. [PMID: 35627144 PMCID: PMC9141459 DOI: 10.3390/genes13050760] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 04/20/2022] [Accepted: 04/24/2022] [Indexed: 11/18/2022] Open
Abstract
Central Core Disease (CCD) is a genetic neuromuscular disorder characterized by the presence of cores in muscle biopsy. The inheritance has been described as predominantly autosomal dominant (AD), and the disease may present as severe neonatal or mild adult forms. Here we report clinical and molecular data on a large cohort of Brazilian CCD patients, including a retrospective clinical analysis and molecular screening for RYR1 variants using Next-Generation Sequencing (NGS). We analyzed 27 patients from 19 unrelated families: four families (11 patients) with autosomal dominant inheritance (AD), two families (3 patients) with autosomal recessive (AR), and 13 sporadic cases. Biallelic RYR1 variants were found in six families (two AR and four sporadic cases) of the 14 molecularly analyzed families (~43%), suggesting a higher frequency of AR inheritance than expected. None of these cases presented a severe phenotype. Facial weakness was more common in biallelic than in monoallelic patients (p = 0.0043) and might be a marker for AR forms. NGS is highly effective for the identification of RYR1 variants in CCD patients, allowing the discovery of a higher proportion of AR cases with biallelic mutations. These data have important implications for the genetic counseling of the families.
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Affiliation(s)
- Ana Cotta
- The SARAH Network of Rehabilitation Hospitals, Av. Amazonas, 5953, Belo Horizonte 30510-000, MG, Brazil; (A.C.); (E.C.); (A.C.J.); (M.M.N.); (J.V.); (M.M.M.); (S.V.N.N.); (R.X.-N.); (A.P.V.); (R.I.T.); (J.F.P.)
| | - Lucas Santos Souza
- Human Genome and Stem Cells Research Center, Genetics and Evolutionary Biology, IBUSP, University of São Paulo, R. do Matao, 106, Cidade Universitária, Sao Paulo 05508-900, SP, Brazil; (L.S.S.); (L.N.F.)
| | - Elmano Carvalho
- The SARAH Network of Rehabilitation Hospitals, Av. Amazonas, 5953, Belo Horizonte 30510-000, MG, Brazil; (A.C.); (E.C.); (A.C.J.); (M.M.N.); (J.V.); (M.M.M.); (S.V.N.N.); (R.X.-N.); (A.P.V.); (R.I.T.); (J.F.P.)
| | - Leticia Nogueira Feitosa
- Human Genome and Stem Cells Research Center, Genetics and Evolutionary Biology, IBUSP, University of São Paulo, R. do Matao, 106, Cidade Universitária, Sao Paulo 05508-900, SP, Brazil; (L.S.S.); (L.N.F.)
| | - Antonio Cunha
- The SARAH Network of Rehabilitation Hospitals, Av. Amazonas, 5953, Belo Horizonte 30510-000, MG, Brazil; (A.C.); (E.C.); (A.C.J.); (M.M.N.); (J.V.); (M.M.M.); (S.V.N.N.); (R.X.-N.); (A.P.V.); (R.I.T.); (J.F.P.)
| | - Monica Machado Navarro
- The SARAH Network of Rehabilitation Hospitals, Av. Amazonas, 5953, Belo Horizonte 30510-000, MG, Brazil; (A.C.); (E.C.); (A.C.J.); (M.M.N.); (J.V.); (M.M.M.); (S.V.N.N.); (R.X.-N.); (A.P.V.); (R.I.T.); (J.F.P.)
| | - Jaquelin Valicek
- The SARAH Network of Rehabilitation Hospitals, Av. Amazonas, 5953, Belo Horizonte 30510-000, MG, Brazil; (A.C.); (E.C.); (A.C.J.); (M.M.N.); (J.V.); (M.M.M.); (S.V.N.N.); (R.X.-N.); (A.P.V.); (R.I.T.); (J.F.P.)
| | - Miriam Melo Menezes
- The SARAH Network of Rehabilitation Hospitals, Av. Amazonas, 5953, Belo Horizonte 30510-000, MG, Brazil; (A.C.); (E.C.); (A.C.J.); (M.M.N.); (J.V.); (M.M.M.); (S.V.N.N.); (R.X.-N.); (A.P.V.); (R.I.T.); (J.F.P.)
| | - Simone Vilela Nunes Neves
- The SARAH Network of Rehabilitation Hospitals, Av. Amazonas, 5953, Belo Horizonte 30510-000, MG, Brazil; (A.C.); (E.C.); (A.C.J.); (M.M.N.); (J.V.); (M.M.M.); (S.V.N.N.); (R.X.-N.); (A.P.V.); (R.I.T.); (J.F.P.)
| | - Rafael Xavier-Neto
- The SARAH Network of Rehabilitation Hospitals, Av. Amazonas, 5953, Belo Horizonte 30510-000, MG, Brazil; (A.C.); (E.C.); (A.C.J.); (M.M.N.); (J.V.); (M.M.M.); (S.V.N.N.); (R.X.-N.); (A.P.V.); (R.I.T.); (J.F.P.)
| | - Antonio Pedro Vargas
- The SARAH Network of Rehabilitation Hospitals, Av. Amazonas, 5953, Belo Horizonte 30510-000, MG, Brazil; (A.C.); (E.C.); (A.C.J.); (M.M.N.); (J.V.); (M.M.M.); (S.V.N.N.); (R.X.-N.); (A.P.V.); (R.I.T.); (J.F.P.)
| | - Reinaldo Issao Takata
- The SARAH Network of Rehabilitation Hospitals, Av. Amazonas, 5953, Belo Horizonte 30510-000, MG, Brazil; (A.C.); (E.C.); (A.C.J.); (M.M.N.); (J.V.); (M.M.M.); (S.V.N.N.); (R.X.-N.); (A.P.V.); (R.I.T.); (J.F.P.)
| | - Julia Filardi Paim
- The SARAH Network of Rehabilitation Hospitals, Av. Amazonas, 5953, Belo Horizonte 30510-000, MG, Brazil; (A.C.); (E.C.); (A.C.J.); (M.M.N.); (J.V.); (M.M.M.); (S.V.N.N.); (R.X.-N.); (A.P.V.); (R.I.T.); (J.F.P.)
| | - Mariz Vainzof
- Human Genome and Stem Cells Research Center, Genetics and Evolutionary Biology, IBUSP, University of São Paulo, R. do Matao, 106, Cidade Universitária, Sao Paulo 05508-900, SP, Brazil; (L.S.S.); (L.N.F.)
- Correspondence:
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Lawal TA, Patankar A, Todd JJ, Razaqyar MS, Chrismer IC, Zhang X, Waite MR, Jain MS, Emile-Backer M, Witherspoon JW, Liu CY, Grunseich C, Meilleur KG. Ryanodine Receptor 1-Related Myopathies: Quantification of Intramuscular Fatty Infiltration from T1-Weighted MRI. J Neuromuscul Dis 2021; 8:657-668. [PMID: 33646171 PMCID: PMC8385519 DOI: 10.3233/jnd-200549] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Background: Ryanodine receptor 1-related myopathy (RYR1-RM) can present with a selective pattern and gradient of intramuscular fatty infiltration (IMFI) on magnetic resonance imaging (MRI). Objective: To demonstrate an automated protocol for quantification of IMFI in the lower extremity muscles of individuals with RYR1-RM using T1-weighted MRI and to examine the relationships of IMFI with motor function and clinical severity. Methods: Axial images of the lower extremity muscles were acquired by T1-weighted fast spin-echo and short tau inversion recovery (STIR) sequences. A modified ImageJ-based program was used for quantification. IMFI data was analyzed by mode of inheritance, motor function, and clinical severity. Results: Upper and lower leg IMFI from 36 genetically confirmed and ambulatory RYR1-RM affected individuals (26 dominant and 10 recessive) were analyzed using Grey-scale quantification. There was no statistically significant difference in IMFI between dominant and recessive cases in upper or lower legs. IMFI in both upper and lower legs was inversely correlated with participant performance on the motor function measure (MFM-32) total score (upper leg: p < 0.001; lower leg: p = 0.003) and the six-minute walk test (6MWT) distance (upper leg: p < 0.001; lower leg: p = 0.010). There was no significant difference in mean IMFI between participants with mild versus severe clinical phenotypes (p = 0.257). Conclusion: A modified ImageJ-based algorithm was able to select and quantify fatty infiltration in a cohort of heterogeneously affected individuals with RYR1-RM. IMFI was not predictive of mode of inheritance but showed strong correlation with motor function and capacity tests including MFM-32 and 6MWT, respectively.
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Affiliation(s)
- Tokunbor A Lawal
- Tissue Injury Branch, National Institute of Nursing Research (NIH), Bethesda, MD, USA
| | - Aneesh Patankar
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke (NIH), Bethesda, MD, USA
| | - Joshua J Todd
- Tissue Injury Branch, National Institute of Nursing Research (NIH), Bethesda, MD, USA
| | - Muslima S Razaqyar
- Tissue Injury Branch, National Institute of Nursing Research (NIH), Bethesda, MD, USA
| | - Irene C Chrismer
- Tissue Injury Branch, National Institute of Nursing Research (NIH), Bethesda, MD, USA
| | - Xuemin Zhang
- Tissue Injury Branch, National Institute of Nursing Research (NIH), Bethesda, MD, USA
| | - Melissa R Waite
- Mark O. Hatfield Clinical Research Center, NIH, Bethesda, MD, USA
| | - Minal S Jain
- Mark O. Hatfield Clinical Research Center, NIH, Bethesda, MD, USA
| | - Magalie Emile-Backer
- Tissue Injury Branch, National Institute of Nursing Research (NIH), Bethesda, MD, USA
| | - Jessica W Witherspoon
- Tissue Injury Branch, National Institute of Nursing Research (NIH), Bethesda, MD, USA
| | - Chia-Ying Liu
- Division of Cardiology, Department of Medicine, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Christopher Grunseich
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke (NIH), Bethesda, MD, USA
| | - Katherine G Meilleur
- Tissue Injury Branch, National Institute of Nursing Research (NIH), Bethesda, MD, USA
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Yang L, Tautz T, Zhang S, Fomina A, Liu H. The current status of malignant hyperthermia. J Biomed Res 2020; 34:75-85. [PMID: 32305961 DOI: 10.7555/jbr.33.20180089] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Malignant hyperthermia (MH) is a rare and life-threatening pharmacogenetic disorder triggered by volatile anesthetics, the depolarizing muscle relaxant succinylcholine, and rarely by strenuous exercise or environmental heat. The exact prevalence of MH is unknown, and it varies from 1:16 000 in Denmark to 1:100 000 in New York State. The underlying mechanism of MH is excessive calcium release from the sarcoplasmic reticulum (SR), leading to uncontrolled skeletal muscle hyper-metabolism. Genetic mutations in ryanodine receptor type 1 ( RYR1) and CACNA1S have been identified in approximately 50% to 86% and 1% of MH-susceptible (MHS) individuals, respectively. Classic clinical symptoms of MH include hypercarbia, sinus tachycardia, masseter spasm, hyperthermia, acidosis, muscle rigidity, hyperkalemia, myoglobinuria, and etc. There are two types of testing for MH: a genetic test and a contracture test. Contracture testing is still being considered as the gold standard for MH diagnosis. Dantrolene is the only available drug approved for the treatment of MH through suppressing the calcium release from SR. Since clinical symptoms of MH are highly variable, it can be difficult to establish a diagnosis of MH. Nevertheless, prompt diagnosis and treatments are crucial to avoid a fatal outcome. Therefore, it is very important for anesthesiologists to raise awareness and understand the characteristics of MH. This review summarizes epidemiology, clinical symptoms, diagnosis and treatments of MH and any new developments.
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Affiliation(s)
- Lukun Yang
- Department of Anesthesiology, the Fifth Affiliated Hospital of Sun Yat-sen University, Zhuhai, Guangdong 519000, China;Department of Anesthesiology and Pain Medicine, University of California Davis Health, Sacramento, CA 95817, USA
| | - Timothy Tautz
- Department of Anesthesiology and Pain Medicine, University of California Davis Health, Sacramento, CA 95817, USA
| | - Shulin Zhang
- Department of Pathology and Laboratory Medicine, College of Medicine, University of Kentucky, Lexington, KY 40506, USA
| | - Alla Fomina
- Department of Physiology and Membrane Biology, University of California Davis Health, Sacramento, CA 95817, USA
| | - Hong Liu
- Department of Anesthesiology and Pain Medicine, University of California Davis Health, Sacramento, CA 95817, USA
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Todd JJ, Sagar V, Lawal TA, Allen C, Razaqyar MS, Shelton MS, Chrismer IC, Zhang X, Cosgrove MM, Kuo A, Vasavada R, Jain MS, Waite M, Rajapakse D, Witherspoon JW, Wistow G, Meilleur KG. Correlation of phenotype with genotype and protein structure in RYR1-related disorders. J Neurol 2018; 265:2506-2524. [PMID: 30155738 PMCID: PMC6182665 DOI: 10.1007/s00415-018-9033-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Revised: 08/17/2018] [Accepted: 08/18/2018] [Indexed: 01/01/2023]
Abstract
Variants in the skeletal muscle ryanodine receptor 1 gene (RYR1) result in a spectrum of RYR1-related disorders. Presentation during infancy is typical and ranges from delayed motor milestones and proximal muscle weakness to severe respiratory impairment and ophthalmoplegia. We aimed to elucidate correlations between genotype, protein structure and clinical phenotype in this rare disease population. Genetic and clinical data from 47 affected individuals were analyzed and variants mapped to the cryo-EM RyR1 structure. Comparisons of clinical severity, motor and respiratory function and symptomatology were made according to the mode of inheritance and affected RyR1 structural domain(s). Overall, 49 RYR1 variants were identified in 47 cases (dominant/de novo, n = 35; recessive, n = 12). Three variants were previously unreported. In recessive cases, facial weakness, neonatal hypotonia, ophthalmoplegia/paresis, ptosis, and scapular winging were more frequently observed than in dominant/de novo cases (all, p < 0.05). Both dominant/de novo and recessive cases exhibited core myopathy histopathology. Clinically severe cases were typically recessive or had variants localized to the RyR1 cytosolic shell domain. Motor deficits were most apparent in the MFM-32 standing and transfers dimension, [median (IQR) 85.4 (18.8)% of maximum score] and recessive cases exhibited significantly greater overall motor function impairment compared to dominant/de novo cases [79.7 (18.8)% vs. 87.5 (17.7)% of maximum score, p = 0.03]. Variant mapping revealed patterns of clinical severity across RyR1 domains, including a structural plane of interest within the RyR1 cytosolic shell, in which 84% of variants affected the bridging solenoid. We have corroborated genotype-phenotype correlations and identified RyR1 regions that may be especially sensitive to structural modification.
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Affiliation(s)
- Joshua J Todd
- Neuromuscular Symptoms Unit, Tissue Injury Branch, National Institute of Nursing Research, National Institutes of Health, 10 Center Drive, Room 2A07, Bethesda, MD, 20892, USA.
| | - Vatsala Sagar
- Section on Molecular Structure and Functional Genomics, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Tokunbor A Lawal
- Neuromuscular Symptoms Unit, Tissue Injury Branch, National Institute of Nursing Research, National Institutes of Health, 10 Center Drive, Room 2A07, Bethesda, MD, 20892, USA
| | - Carolyn Allen
- Neuromuscular Symptoms Unit, Tissue Injury Branch, National Institute of Nursing Research, National Institutes of Health, 10 Center Drive, Room 2A07, Bethesda, MD, 20892, USA
| | - Muslima S Razaqyar
- Neuromuscular Symptoms Unit, Tissue Injury Branch, National Institute of Nursing Research, National Institutes of Health, 10 Center Drive, Room 2A07, Bethesda, MD, 20892, USA
| | - Monique S Shelton
- Neuromuscular Symptoms Unit, Tissue Injury Branch, National Institute of Nursing Research, National Institutes of Health, 10 Center Drive, Room 2A07, Bethesda, MD, 20892, USA
| | - Irene C Chrismer
- Neuromuscular Symptoms Unit, Tissue Injury Branch, National Institute of Nursing Research, National Institutes of Health, 10 Center Drive, Room 2A07, Bethesda, MD, 20892, USA
| | - Xuemin Zhang
- Neuromuscular Symptoms Unit, Tissue Injury Branch, National Institute of Nursing Research, National Institutes of Health, 10 Center Drive, Room 2A07, Bethesda, MD, 20892, USA
| | - Mary M Cosgrove
- Neuromuscular Symptoms Unit, Tissue Injury Branch, National Institute of Nursing Research, National Institutes of Health, 10 Center Drive, Room 2A07, Bethesda, MD, 20892, USA
| | - Anna Kuo
- Neuromuscular Symptoms Unit, Tissue Injury Branch, National Institute of Nursing Research, National Institutes of Health, 10 Center Drive, Room 2A07, Bethesda, MD, 20892, USA
| | - Ruhi Vasavada
- Mark O. Hatfield Clinical Research Center, Rehabilitation Medicine Department, National Institutes of Health, Bethesda, MD, USA
| | - Minal S Jain
- Mark O. Hatfield Clinical Research Center, Rehabilitation Medicine Department, National Institutes of Health, Bethesda, MD, USA
| | - Melissa Waite
- Mark O. Hatfield Clinical Research Center, Rehabilitation Medicine Department, National Institutes of Health, Bethesda, MD, USA
| | - Dinusha Rajapakse
- Section on Molecular Structure and Functional Genomics, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Jessica W Witherspoon
- Neuromuscular Symptoms Unit, Tissue Injury Branch, National Institute of Nursing Research, National Institutes of Health, 10 Center Drive, Room 2A07, Bethesda, MD, 20892, USA
| | - Graeme Wistow
- Section on Molecular Structure and Functional Genomics, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Katherine G Meilleur
- Neuromuscular Symptoms Unit, Tissue Injury Branch, National Institute of Nursing Research, National Institutes of Health, 10 Center Drive, Room 2A07, Bethesda, MD, 20892, USA
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Abstract
This article reviews advancements in the genetics of malignant hyperthermia, new technologies and approaches for its diagnosis, and the existing limitations of genetic testing for malignant hyperthermia. It also reviews the various RYR1-related disorders and phenotypes, such as myopathies, exertional rhabdomyolysis, and bleeding disorders, and examines the connection between these disorders and malignant hyperthermia.
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Abstract
BACKGROUND Malignant hyperthermia (MH) is triggered by reactions to anesthetics. Reports link nonanesthetic-induced MH-like reactions to a variety of disorders. The objective of the authors was to retrospectively investigate the reasons for referrals for MH testing in nonanesthetic cases and assess their phenotype. In addition, the response to the administration of oral dantrolene in nonanesthetic probands with positive caffeine-halothane contracture test (CHCT) was investigated. METHODS Following institutional research ethics board approval, probands without reaction to anesthesia, who underwent CHCT, were selected. Clinical details and response to dantrolene were analyzed. RESULTS In total, 87 of 136 (64%) patients referred for nonanesthetic indications tested positive to the CHCT. Of these, 47 with a high creatine kinase (CK), 9 with exercise-induced rhabdomyolysis and/or exercise intolerance, 2 with high CK and exercise-induced rhabdomyolysis and/or exercise intolerance, 15 with postviral chronic fatigue, and 14 with muscle weakness of unknown etiology had a positive CHCT. These patients had a higher CK compared with those with negative CHCT. Oral dantrolene improved the musculoskeletal symptoms in 28 of 34 (82%) CHCT-positive patients. Response to treatment was associated with a significantly higher pretreatment CK and a greater posttreatment CK reduction. CONCLUSIONS A positive CHCT may represent more than simply an anesthetic-related disorder. Individuals with positive CHCTs may exhibit muscle symptoms without exposure to MH-triggering anesthetics. Oral dantrolene may be useful in alleviating these symptoms.
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Homozygote und „compound“-heterozygote RYR1-Mutationen. Anaesthesist 2014; 63:643-50. [DOI: 10.1007/s00101-014-2351-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Revised: 06/02/2014] [Accepted: 06/03/2014] [Indexed: 11/25/2022]
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Klingler W, Heiderich S, Girard T, Gravino E, Heffron JJA, Johannsen S, Jurkat-Rott K, Rüffert H, Schuster F, Snoeck M, Sorrentino V, Tegazzin V, Lehmann-Horn F. Functional and genetic characterization of clinical malignant hyperthermia crises: a multi-centre study. Orphanet J Rare Dis 2014; 9:8. [PMID: 24433488 PMCID: PMC3896768 DOI: 10.1186/1750-1172-9-8] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2013] [Accepted: 01/08/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Malignant hyperthermia (MH) is a rare pharmacogenetic disorder which is characterized by life-threatening metabolic crises during general anesthesia. Classical triggering substances are volatile anesthetics and succinylcholine (SCh). The molecular basis of MH is excessive release of Ca2+ in skeletal muscle principally by a mutated ryanodine receptor type 1 (RyR1). To identify factors explaining the variable phenotypic presentation and complex pathomechanism, we analyzed proven MH events in terms of clinical course, muscle contracture, genetic factors and pharmocological triggers. METHODS In a multi-centre study including seven European MH units, patients with a history of a clinical MH episode confirmed by susceptible (MHS) or equivocal (MHE) in vitro contracture tests (IVCT) were investigated. A test result is considered to be MHE if the muscle specimens develop pathological contractures in response to only one of the two test substances, halothane or caffeine. Crises were evaluated using a clinical grading scale (CGS), results of IVCT and genetic screening. The effects of SCh and volatile anesthetics on Ca2+ release from sarcoplasmic reticulum (SR) were studied in vitro. RESULTS A total of 200 patients met the inclusion criteria. Two MH crises (1%) were triggered by SCh (1 MHS, 1 MHE), 18% by volatile anesthetics and 81% by a combination of both. Patients were 70% male and 50% were younger than 12 years old. Overall, CGS was in accord with IVCT results. Crises triggered by enflurane had a significantly higher CGS compared to halothane, isoflurane and sevoflurane. Of the 200 patients, 103 carried RyR1 variants, of which 14 were novel. CGS varied depending on the location of the mutation within the RyR1 gene. In contrast to volatile anesthetics, SCh did not evoke Ca2+ release from isolated rat SR vesicles. CONCLUSIONS An MH event could depend on patient-related risk factors such as male gender, young age and causative RyR1 mutations as well as on the use of drugs lowering the threshold of myoplasmic Ca2+ release. SCh might act as an accelerant by promoting unspecific Ca2+ influx via the sarcolemma and indirect RyR1 activation. Most MH crises develop in response to the combined administration of SCh and volatile anesthetics.
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Affiliation(s)
- Werner Klingler
- Department of Neuroanesthesiology, Ulm University, Ludwig-Heilmeyer-Str. 2, Günzburg 89312, Germany
- Division of Neurophysiology, Ulm University, Albert-Einstein Allee 11, Ulm 89081, Germany
- Rare Disease Center, University Hospital Ulm, Ulm 89081, Germany
| | - Sebastian Heiderich
- Department of Neuroanesthesiology, Ulm University, Ludwig-Heilmeyer-Str. 2, Günzburg 89312, Germany
- Division of Neurophysiology, Ulm University, Albert-Einstein Allee 11, Ulm 89081, Germany
- Department of Anesthesiology and Intensive Care Medicine, Hannover Medical School, Carl-Neuberg-Strasse 1, Hannover 30625, Germany
| | | | | | | | - Stephan Johannsen
- Department of Anesthesia and Critical Care, University of Würzburg, Würzburg, Germany
| | - Karin Jurkat-Rott
- Division of Neurophysiology, Ulm University, Albert-Einstein Allee 11, Ulm 89081, Germany
- Rare Disease Center, University Hospital Ulm, Ulm 89081, Germany
| | - Henrik Rüffert
- University of Leipzig, Helios Kliniken Leipziger Land Leipzig, Germany
| | - Frank Schuster
- Department of Anesthesia and Critical Care, University of Würzburg, Würzburg, Germany
| | - Marc Snoeck
- Department of Anesthesia, Canisius-Wilhelmina Hospital, University of Nijmegen, Nijmegen, The Netherlands
| | - Vincenzo Sorrentino
- Molecular Medicine Section, Department of Molecular and Developmental Medicine, University of Siena, via A. Moro 2, Siena 53100, Italy
| | | | - Frank Lehmann-Horn
- Division of Neurophysiology, Ulm University, Albert-Einstein Allee 11, Ulm 89081, Germany
- Rare Disease Center, University Hospital Ulm, Ulm 89081, Germany
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Brandom BW, Bina S, Wong CA, Wallace T, Visoiu M, Isackson PJ, Vladutiu GD, Sambuughin N, Muldoon SM. Ryanodine receptor type 1 gene variants in the malignant hyperthermia-susceptible population of the United States. Anesth Analg 2013; 116:1078-1086. [PMID: 23558838 PMCID: PMC3633164 DOI: 10.1213/ane.0b013e31828a71ff] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Mutations in the ryanodine receptor type 1 gene (RYR1) that encodes the skeletal muscle-specific intracellular calcium (Ca(2+)) release channel are a cause of malignant hyperthermia (MH). In this study, we examined RYR1 mutations in a large number of North American MH-susceptible (MHS) subjects without prior genetic diagnosis. METHODS RYR1 was examined in 120 unrelated MHS subjects from the United States in a tiered manner. The α-1 subunit of the dihydropyridine receptor gene (CACNA1S) was screened for 4 variants in subjects in whom no abnormality was found in ≥ 100 exons of RYR1. RESULTS Ten known causative MH mutations were found in 26 subjects. Variants of uncertain significance in RYR1 were found in 36 subjects, 16 of which are novel. Novel variants in both RYR1 and CACNA1S were found in the 1 subject who died of MH. Two RYR1 variants were found in 4 subjects. Variants of uncertain significance were found outside and inside the hotspots of RYR1. Maximal contractures in the caffeine-halothane contracture test were greater in those who had a known MH mutation or variant of uncertain significance in RYR1 than in those who did not. CONCLUSIONS The identification of novel RYR1 variants and previously observed RYR1 variants of uncertain significance in independent MHS families is necessary for demonstrating the significance of these variants for MH susceptibility and supports the need for functional studies of these variants. Continued reporting of the clinical phenotypes of MH is necessary for interpretation of genetic findings, especially because the pathogenicity of most of these genetic variants associated with MHS remains to be elucidated.
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Affiliation(s)
- Barbara W Brandom
- From the Department of Anesthesiology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania; Department of Anesthesiology, Uniformed Services University of the Health Sciences, Bethesda, Maryland; Department of Anesthesiology, Northwestern University, Chicago, Illinois; Children's Hospital, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania; and Departments of Pediatrics, Neurology, Pathology and Anatomical Sciences, School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York
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11
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Dlamini N, Voermans NC, Lillis S, Stewart K, Kamsteeg EJ, Drost G, Quinlivan R, Snoeck M, Norwood F, Radunovic A, Straub V, Roberts M, Vrancken AFJE, van der Pol WL, de Coo RIFM, Manzur AY, Yau S, Abbs S, King A, Lammens M, Hopkins PM, Mohammed S, Treves S, Muntoni F, Wraige E, Davis MR, van Engelen B, Jungbluth H. Mutations in RYR1 are a common cause of exertional myalgia and rhabdomyolysis. Neuromuscul Disord 2013; 23:540-8. [PMID: 23628358 DOI: 10.1016/j.nmd.2013.03.008] [Citation(s) in RCA: 143] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Revised: 03/08/2013] [Accepted: 03/12/2013] [Indexed: 12/23/2022]
Abstract
Mutations in the skeletal muscle ryanodine receptor (RYR1) gene are a common cause of neuromuscular disease, ranging from various congenital myopathies to the malignant hyperthermia (MH) susceptibility trait without associated weakness. We sequenced RYR1 in 39 unrelated families with rhabdomyolysis and/or exertional myalgia, frequent presentations in the neuromuscular clinic that often remain unexplained despite extensive investigations. We identified 9 heterozygous RYR1 mutations/variants in 14 families, 5 of them (p.Lys1393Arg; p.Gly2434Arg; p.Thr4288_Ala4290dup; p.Ala4295Val; and p.Arg4737Gln) previously associated with MH. Index cases presented from 3 to 45 years with rhabdomyolysis, with or without exertional myalgia (n=12), or isolated exertional myalgia (n=2). Rhabdomyolysis was commonly triggered by exercise and heat and, less frequently, viral infections, alcohol and drugs. Most cases were normally strong and had no personal MH history. Inconsistent additional features included heat intolerance, and cold-induced muscle stiffness. Muscle biopsies showed mainly subtle changes. Familial RYR1 mutations were confirmed in relatives with similar or no symptoms. These findings suggest that RYR1 mutations may account for a substantial proportion of patients presenting with unexplained rhabdomyolysis and/or exertional myalgia. Associated clinico-pathological features may be subtle and require a high degree of suspicion. Additional family studies are paramount in order to identify potentially MH susceptible relatives.
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Affiliation(s)
- N Dlamini
- Department of Paediatric Neurology, Neuromuscular Service, Evelina's Children Hospital, Guy's & St. Thomas' Hospital NHS Foundation Trust, London, UK
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12
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A mathematical model to improve on phenotyping for molecular genetic research in malignant hyperthermia. Pharmacogenet Genomics 2012; 19:972-8. [PMID: 19890226 DOI: 10.1097/fpc.0b013e3283339c08] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND The in-vitro contracture test is the standard test to diagnose malignant hyperthermia (MH) susceptibility. Maximum sensitivity is important for patient safety. For scientific purposes, the reduced specificity of contracture testing is a major drawback, and precise phenotyping is of utmost importance. Our study aimed to improve phenotyping for MH susceptibility to more accurately select patients for molecular genetic research in MH, thus, improving the probability to detect novel MH associated variants. METHODS Patients who underwent contracture and molecular genetic testing were selected from the database of two MH investigation centres (Basel and Leipzig). The area under the curve of halothane and caffeine contracture tests was calculated and a logistic regression model was applied to determine the odds of carrying a MH associated genetic variant. This model was subsequently applied to patients without familial MH related genetic variant. RESULTS Validation of the logistic regression model showed 98% concordance with molecular genetic results. Among patients with unclear in-vitro contracture test diagnosis (MH equivocal), half of the mutation carriers were classified as positive by the model, whereas 86% of those without familial mutation were classified as negative. Excluding the MH equivocal group, the model showed sensitivity of 0.99 (95% confidence interval: 0.95-0.99) and specificity 0.98 (95% confidence interval: 0.94-0.99), respectively, to identify genetically positive MH individuals. CONCLUSION Our model is a valuable tool to select patients from MH families for further molecular genetic research. This preselection increases the probability of successful molecular genetic research and is important when available resources are limited.
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13
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Tammaro A, Di Martino A, Bracco A, Cozzolino S, Savoia G, Andria B, Cannavo A, Spagnuolo M, Piluso G, Aurino S, Nigro V. Novel missense mutations and unexpected multiple changes of RYR1 gene in 75 malignant hyperthermia families. Clin Genet 2011; 79:438-47. [PMID: 20681998 DOI: 10.1111/j.1399-0004.2010.01493.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Malignant hyperthermia (MH) is an autosomal dominant pharmacogenetic disorder of skeletal muscle characterized by disturbance of intracellular calcium homeostasis in the sarcoplasmic reticulum. Mutations of the ryanodine receptor 1 (RYR1) gene account for most cases, with some studies claiming up to 86% of mutations in this locus. However, RYR1 gene is large and variants are common even in the normal population. We examined 54 families with MH susceptibility and 21 diagnosed with equivocal MH. Thirty-five were selected for an anesthetic reaction, whereas the remainder for hyperCKemia. In these, we studied all 106 exons of the RYR1 gene. When no mutation was found, we also screened: sodium channel voltage-gated, type IV alpha subunit (SCN4A), calcium channel voltage-dependent, L type, alpha 1S subunit (CACNA1S), and L-type voltage-gated calcium channel alpha 2/delta-subunit (CACNL2A). Twenty-nine different RYR1 mutations were discovered in 40 families. Three other MH genes were tested in negative cases. Fourteen RYR1 amino acid changes were novel, of which 12 were located outside the mutational 'hot spots'. In two families, the known mutation p.R3903Q was also observed in malignant hyperthermia-nonsusceptible (MHN) individuals. Unexpectedly, four changes were also found in the same family and two in another. Our study confirms that MH is genetically heterogeneous and that a consistent number of cases are not due to RYR1 mutations. The discordance between in vitro contracture test status and the presence of a proven causative RYR1 mutation suggests that the penetrance may vary due to as yet unknown factors.
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Affiliation(s)
- A Tammaro
- Centro di Biotecnologie, AORN Cardarelli, Napoli, Italy
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14
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Ryanodine receptor type 1 gene mutations found in the Canadian malignant hyperthermia population. Can J Anaesth 2011; 58:504-13. [DOI: 10.1007/s12630-011-9494-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2010] [Accepted: 03/17/2011] [Indexed: 01/31/2023] Open
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15
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Klingler W, Lehmann-Horn F, Schulte-Sasse U. [Hotline for malignant hyperthermia. New telephone number for the German nationwide 24 h service center: 08221/9600]. Anaesthesist 2011; 60:172-4. [PMID: 21308355 DOI: 10.1007/s00101-011-1851-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- W Klingler
- Neuroanästhesie, Neurochirurgische Universitätsklinik Ulm, BKH Günzburg, Ludwig Heilmeyer Strasse 2, Günzburg, Germany.
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16
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17
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Use of the caffeine-halothane contracture test for the diagnosis of malignant hyperthermia in Brazil. Braz J Med Biol Res 2010; 43:549-56. [PMID: 20464345 DOI: 10.1590/s0100-879x2010007500045] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2009] [Accepted: 04/30/2010] [Indexed: 11/22/2022] Open
Abstract
Malignant hyperthermia (MH) is a pharmacogenetic disease triggered by volatile anesthetics and succinylcholine. Deaths due to MH have been reported in Brazil. The first Malignant Hyperthermia Diagnostic and Research Center in Latin America was inaugurated in 1993 at the Federal University of Rio de Janeiro, Brazil. The center followed the diagnostic protocols of the North America MH Group, in which the contractures of biopsies from the vastus lateralis muscle are analyzed after exposure to caffeine and halothane (CHCT). CHCT was performed in individuals who survived, their relatives and those with signs/symptoms somewhat related to MH susceptibility (MHS). Here, we report data from 194 patients collected over 16 years. The Southeast (N = 110) and South (N = 71) represented the majority of patients. Median age was 25 (4-70) years, with similar numbers of males (104) and females (90). MHS was found in 90 patients and 104 patients were normal. Abnormal responses to both caffeine and halothane were observed in 59 patients and to caffeine or halothane in 20 and 11 patients, respectively. The contracture of biopsies from MHS exposed to caffeine and halothane was 1.027 +/- 0.075 g (N = 285) and 4.021 +/- 0.255 g (N = 226), respectively. MHS was found in patients with either low or high blood creatine kinase and also, with a low score on the clinical grading scale. Thus, these parameters cannot be used with certainty to predict MHS. We conclude that the CHCT protocol described by the North America MH Group contributed to identification of MHS in suspected individuals at an MH center in Brazil with 100% sensitivity and 65.7% specificity.
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18
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Lobo PA, Van Petegem F. Crystal structures of the N-terminal domains of cardiac and skeletal muscle ryanodine receptors: insights into disease mutations. Structure 2010; 17:1505-14. [PMID: 19913485 DOI: 10.1016/j.str.2009.08.016] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2009] [Revised: 08/12/2009] [Accepted: 08/22/2009] [Indexed: 11/17/2022]
Abstract
Ryanodine receptors (RyRs) are channels governing the release of Ca(2+) from the sarcoplasmic or endoplasmic reticulum. They are required for the contraction of both skeletal (RyR1) and cardiac (RyR2) muscles. Mutations in both RyR1 and RyR2 have been associated with severe genetic disorders, but high-resolution data describing the disease variants in detail have been lacking. Here we present the crystal structures of the N-terminal domains of both RyR2 (1-217) and RyR1 (9-205) at 2.55 A and 2.9 A, respectively. The domains map in a hot spot region for disease mutations. Both structures consist of a core beta trefoil domain flanked by an alpha helix. Crystal structures of two RyR2 disease mutants, A77V (2.2 A) and V186M (1.7 A), show that the mutations cause distinct local changes in the surface of the protein. A RyR2 deletion mutant causes significant changes in the thermal stability. The disease positions highlight two putative binding interfaces required for normal RyR function.
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Affiliation(s)
- Paolo Antonio Lobo
- University of British Columbia, Department of Biochemistry and Molecular Biology, Vancouver, BC V6T 1Z3 Canada
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19
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Lee JW, Yi JS, Lee JR, Kim DC. Anesthetic experience for patients with malignant hyperthermia susceptibility determined by molecular genetic test: A report of 2 cases. Korean J Anesthesiol 2009; 57:387-391. [PMID: 30625893 DOI: 10.4097/kjae.2009.57.3.387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Malignant hyperthermia (MH) is a potentially fatal pharmacogenetic disorder manifested as a life threatening hypermetabolic crisis in susceptible individuals following exposure to inhalation anesthetics and to depolarizing muscle relaxants. The preoperative diagnosis of MH susceptibility is difficult. The gold standard for determination of MH susceptibility is the in vitro contracture test. However, it is invasive, requiring skeletal muscle biopsy and is not widely available. Recent advances in genetic testing for mutations that result in MH during anesthesia have helped some genetic test have limitations in clinical application due to the diversity of mutations. In Korea, we found the RYR1 genetic mutation by molecular genetic testing for MH susceptibility in a family for which MH had occurred. Based on the results of genetic testing, we could known MH susceptibility of 2 patients. We believe that the genetic testing for MH can be developed and used with some limitations in clinical settings in Korea.
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Affiliation(s)
- Jeong Woo Lee
- Department of Anesthesiology and Pain Medicine, Chonbuk National University Medical School, Jeonju, Korea.
| | - Ji Sun Yi
- Department of Anesthesiology and Pain Medicine, Chonbuk National University Medical School, Jeonju, Korea.
| | - Jun Rye Lee
- Department of Anesthesiology and Pain Medicine, Chonbuk National University Medical School, Jeonju, Korea.
| | - Dong Chan Kim
- Department of Anesthesiology and Pain Medicine, Chonbuk National University Medical School, Jeonju, Korea.
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20
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Hernandez JF, Secrest JA, Hill L, McClarty SJ. Scientific advances in the genetic understanding and diagnosis of malignant hyperthermia. J Perianesth Nurs 2009; 24:19-31; quiz 32-4. [PMID: 19185818 DOI: 10.1016/j.jopan.2008.12.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2008] [Revised: 11/15/2008] [Accepted: 12/03/2008] [Indexed: 02/06/2023]
Abstract
Malignant hyperthermia (MH), a potentially fatal disorder triggered by certain types of general anesthesia, has received much attention in the scientific literature. From the first case report in 1960 until the present, hundreds of studies have been conducted. The diagnosis of MH has evolved from subjective assumptions by family history and clinical diagnosis to more sophisticated laboratory testing. A genetic basis for MH was recognized in the early 1990s and, since then, complex genetic pathways have been demonstrated. The purpose of this paper is to summarize the research literature on what is known scientifically about the diagnosis and genetic basis of MH.
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21
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Levano S, Vukcevic M, Singer M, Matter A, Treves S, Urwyler A, Girard T. Increasing the number of diagnostic mutations in malignant hyperthermia. Hum Mutat 2009; 30:590-8. [DOI: 10.1002/humu.20878] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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22
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Gillies RL, Bjorksten AR, Davis M, Du Sart D. Identification of genetic mutations in Australian malignant hyperthermia families using sequencing of RYR1 hotspots. Anaesth Intensive Care 2008; 36:391-403. [PMID: 18564801 DOI: 10.1177/0310057x0803600311] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Advances in analysis of the RYR1 gene (which encodes the skeletal muscle ryanodine receptor) show that genetic examination is a useful adjunct to the in vitro contracture test in the diagnosis of malignant hyperthermia, as defects in RYR1 have been shown to be responsible for malignant hyperthermia susceptibility. DNA from 34 malignant hyperthermia susceptible individuals and four malignant hyperthermia equivocal subjects was examined using direct sequencing of 'hot-spots' in the RYR1 gene to identify mutations associated with malignant hyperthermia. Seven different causative mutations (as defined by the European Malignant Hyperthermia Group) in nine malignant hyperthermia susceptible individuals were identified. In another six malignant hyperthermia susceptible individuals, five different published but as yet functionally uncharacterised mutations were identified. A further three as yet unpublished and functionally uncharacterised (novel) mutations were identified in three malignant hyperthermia susceptible samples. If the novel and previously published mutations prove to be functionally associated with calcium homeostasis, then this method of analysis achieved a mutation detection rate of 47%. Based on the number of relatives presenting to our unit in the study period, the muscle biopsy rate would have decreased by 25%. That we only identified a genetic defect in RYR1 in 47% of in vitro contracture test positive individuals suggests that there are other areas in RYR1 where pathogenic mutations may occur and that RYR1 may not be the sole gene associated with malignant hyperthermia. It may also reflect a less than 100% specificity of the in vitro contracture test.
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Affiliation(s)
- R L Gillies
- Department of Anaesthesia and Pain Management, Royal Melbourne Hospital, Parkville, Australia
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23
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Abstract
The term "malignant hyperthermia" (MH), regarded as the typical anaesthetic disease, refers to a clinical syndrome of varying intensity (from abortive courses to fulminant crises) and develops only under exposure of certain triggering substances or mechanisms. MH is caused by a defect in the ryanodine receptor subtype 1, which can often be proved genetically. Furthermore, it may also be generated by other mechanisms which disturb the membranous integrity of skeletal muscle cells (e.g. some myotonias, muscular dystrophies, malformation syndromes). Hyperthermia is only one of a number of life-threatening symptoms that may occur during a fulminant crisis, which ultimately results from an excessive release of calcium into the cytoplasm of muscle cells. Due to a current good knowledge about classical triggers, symptoms and therapeutic interventions, a clinical MH presentation may successfully be treated in the perioperative period. However, it appears to be likely that there are unreported cases outside hospitals since atypical courses or alternative MH triggers (e.g. alcohol, drugs, physical stress) may impair the correct diagnosis. In contrast severe hyperthermia can also arise from other drug-induced diseases, e.g. the neuroleptic malignant syndrome or the serotonin syndrome.
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Affiliation(s)
- H Rüffert
- Klinik für Anästhesiologie und Intensivtherapie, Universitätsklinikum Leipzig AöR, Liebigstr. 20, 04103 Leipzig.
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Islander G, Rydenfelt K, Ranklev E, Bodelsson M. Male preponderance of patients testing positive for malignant hyperthermia susceptibility. Acta Anaesthesiol Scand 2007; 51:614-20. [PMID: 17430325 DOI: 10.1111/j.1399-6576.2007.01293.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Malignant hyperthermia susceptibility is diagnosed using an in vitro contracture test (IVCT). In families in which the mutation is known, genetic tests are also available. The inheritance pattern is regarded as autosomal dominant, which predicts equal proportions of men and women affected. The aim of this study was to investigate whether there were sex differences in the diagnostic outcome of the 1407 patients tested for malignant hyperthermia in Sweden between 1985 and 2005. METHODS Information about sex, diagnosis, IVCT result and kinship was analysed. Comparisons were made between the two sexes. Probands and relatives were analysed separately in order to eliminate bias caused by the type of surgery performed in the two sexes. RESULTS Males, more than females, revealed a pathological outcome in IVCT. Amongst male relatives, the fraction of pathological outcome in IVCT was 0.70 [95% confidence interval (CI), 0.66-0.74]; the corresponding value for females was 0.40 (95% CI, 0.36-0.44). CONCLUSION A significant difference was observed in the sex distribution of outcome of IVCT, with significantly more males revealing a pathological IVCT. This indicates the influence of one or several factors related to sex in the outcome of IVCT, for example different expression of calcium handling proteins in the sexes, a complex pattern of inheritance or unknown environmental factors.
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Affiliation(s)
- G Islander
- Department of Anaesthesia and Intensive Care, MH Unit, Lund University Hospital, SE-221 85 Lund, Sweden.
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25
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Rosenberg H, Davis M, James D, Pollock N, Stowell K. Malignant hyperthermia. Orphanet J Rare Dis 2007; 2:21. [PMID: 17456235 PMCID: PMC1867813 DOI: 10.1186/1750-1172-2-21] [Citation(s) in RCA: 264] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2007] [Accepted: 04/24/2007] [Indexed: 11/10/2022] Open
Abstract
Malignant hyperthermia (MH) is a pharmacogenetic disorder of skeletal muscle that presents as a hypermetabolic response to potent volatile anesthetic gases such as halothane, sevoflurane, desflurane and the depolarizing muscle relaxant succinylcholine, and rarely, in humans, to stresses such as vigorous exercise and heat. The incidence of MH reactions ranges from 1:5,000 to 1:50,000-100,000 anesthesias. However, the prevalence of the genetic abnormalities may be as great as one in 3,000 individuals. MH affects humans, certain pig breeds, dogs, horses, and probably other animals. The classic signs of MH include hyperthermia to marked degree, tachycardia, tachypnea, increased carbon dioxide production, increased oxygen consumption, acidosis, muscle rigidity, and rhabdomyolysis, all related to a hypermetabolic response. The syndrome is likely to be fatal if untreated. Early recognition of the signs of MH, specifically elevation of end-expired carbon dioxide, provides the clinical diagnostic clues. In humans the syndrome is inherited in autosomal dominant pattern, while in pigs in autosomal recessive. The pathophysiologic changes of MH are due to uncontrolled rise of myoplasmic calcium, which activates biochemical processes related to muscle activation. Due to ATP depletion, the muscle membrane integrity is compromised leading to hyperkalemia and rhabdomyolysis. In most cases, the syndrome is caused by a defect in the ryanodine receptor. Over 90 mutations have been identified in the RYR-1 gene located on chromosome 19q13.1, and at least 25 are causal for MH. Diagnostic testing relies on assessing the in vitro contracture response of biopsied muscle to halothane, caffeine, and other drugs. Elucidation of the genetic changes has led to the introduction, on a limited basis so far, of genetic testing for susceptibility to MH. As the sensitivity of genetic testing increases, molecular genetics will be used for identifying those at risk with greater frequency. Dantrolene sodium is a specific antagonist of the pathophysiologic changes of MH and should be available wherever general anesthesia is administered. Thanks to the dramatic progress in understanding the clinical manifestation and pathophysiology of the syndrome, the mortality from MH has dropped from over 80% thirty years ago to less than 5%.
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Affiliation(s)
- Henry Rosenberg
- Department of Medical Education and Clinical Research, Saint Barnabas Medical Center, Livingston, NJ 07039, USA
| | - Mark Davis
- Department of Medical Education and Clinical Research, Saint Barnabas Medical Center, Livingston, NJ 07039, USA
| | - Danielle James
- Department of Medical Education and Clinical Research, Saint Barnabas Medical Center, Livingston, NJ 07039, USA
| | - Neil Pollock
- Department of Medical Education and Clinical Research, Saint Barnabas Medical Center, Livingston, NJ 07039, USA
| | - Kathryn Stowell
- Department of Medical Education and Clinical Research, Saint Barnabas Medical Center, Livingston, NJ 07039, USA
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Broman M, Islander G, Müller CR, Ranklev-Twetman E. Malignant hyperthermia and central core disease causative mutations in Swedish patients. Acta Anaesthesiol Scand 2007; 51:50-3. [PMID: 17081152 DOI: 10.1111/j.1399-6576.2006.01165.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
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. METHODS In 27 MH susceptible (MHS) probands and four MH negative (MHN) probands, exons 17, 39, 40, 45 and 46 of the RYR1 gene were screened for MH causative mutations. In addition, in three patients with established central core disease (CCD), exons 17, 39, 40, 45 and 46 and exons 95, 100, 101 and 102 were screened for MH and CCD causative mutations. All screenings were performed by direct sequencing of the entire exons. RESULTS MH causative mutations were found in five of the 27 MHS probands (19%). CCD causative mutations were found in two of three CCD patients in the C-terminal exons. None of the CCD patients showed a mutation in N-terminal exon 17 or in the central exons. CONCLUSIONS In a Swedish population, screening of N-terminal exon 17 and the central exons for MH causative mutations in the RYR1 gene covers 19% of families. Thus, other mutations must also be responsible for MH susceptibility in Sweden. Although the number of CCD patients in this study was small, screening of the C-terminal exons for CCD causative mutations seems to be a promising tool in the process of making a diagnosis.
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Affiliation(s)
- M Broman
- Department of Anaesthesiology and Intensive Care, Lund University Hospital, Lund, Sweden.
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Durham WJ, Wehrens XHT, Sood S, Hamilton SL. Diseases associated with altered ryanodine receptor activity. Subcell Biochem 2007; 45:273-321. [PMID: 18193641 DOI: 10.1007/978-1-4020-6191-2_10] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Mutations in two intracellular Ca2+ release channels or ryanodine receptors (RyR1 and RyR2) are associated with a number of human skeletal and cardiac diseases. This chapter discusses these diseases in terms of known mechanisms, controversies, and unanswered questions. We also compare the cardiac and skeletal muscle diseases to explore common mechanisms.
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Affiliation(s)
- W J Durham
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
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28
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Robinson R, Carpenter D, Shaw MA, Halsall J, Hopkins P. Mutations inRYR1in malignant hyperthermia and central core disease. Hum Mutat 2006; 27:977-89. [PMID: 16917943 DOI: 10.1002/humu.20356] [Citation(s) in RCA: 337] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The RYR1 gene encodes the skeletal muscle isoform ryanodine receptor and is fundamental to the process of excitation-contraction coupling and skeletal muscle calcium homeostasis. Mapping to chromosome 19q13.2, the gene comprises 106 exons and encodes a protein of 5,038 amino acids. Mutations in the gene have been found in association with several diseases: the pharmacogenetic disorder, malignant hyperthermia (MH); and three congenital myopathies, including central core disease (CCD), multiminicore disease (MmD), and in an isolated case of a congenital myopathy characterized on histology by cores and rods. The majority of gene mutations reported are missense changes identified in cases of MH and CCD. In vitro analysis has confirmed that alteration of normal calcium homeostasis is a functional consequence of some of these changes. Genotype-phenotype correlation studies performed using data from MH and CCD patients have also suggested that mutations may be associated with a range of disease severity phenotypes. This review aims to summarize the current understanding of RYR1 mutations reported in association with MH and CCD and the present viewpoint on the use of mutation data to aid clinical diagnosis of these conditions.
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Affiliation(s)
- Rachel Robinson
- Malignant Hyperthermia Investigation Unit, St James' University Hospital, Leeds, United Kingdom.
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29
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Monnier N, Kozak-Ribbens G, Krivosic-Horber R, Nivoche Y, Qi D, Kraev N, Loke J, Sharma P, Tegazzin V, Figarella-Branger D, Roméro N, Mezin P, Bendahan D, Payen JF, Depret T, Maclennan DH, Lunardi J. Correlations between genotype and pharmacological, histological, functional, and clinical phenotypes in malignant hyperthermia susceptibility. Hum Mutat 2005; 26:413-25. [PMID: 16163667 DOI: 10.1002/humu.20231] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Malignant hyperthermia susceptibility (MHS) is a subclinical pharmacogenetic disorder caused by an impairment of skeletal muscle calcium homeostasis in response to triggering agents. While in vitro contracture testing (IVCT) is the gold standard for defining MHS, molecular analysis is increasingly used to diagnosis MHS. Mutations associated with MHS have been reported in two genes: RYR1 and CACNA1S. Mutations in RYR1 are also responsible for central core disease (CCD), a myopathy that can be associated with a positive IVCT response. We report here the results of correlation studies performed with molecular, pharmacological, histological, and functional data obtained in 175 families (referred to as confirmed (129) or potential (46) MHS families). Extensive molecular analysis allowed us to identify a variant in 60% of the confirmed MHS families, and resulted in the characterization of 11 new variants in the RYR1 gene. Most mutations clustered to MH1 and MH2 domains of RYR1. Functional analysis allowed us to assign a causative role for seven MHS mutations that we propose to add to the panel of MHS mutations used for genetic testing. The use of genetic data to determine MHS status led to a 99.5% sensitivity for IVCT. IVCT-positive/mutation-negative diagnoses were analyzed not only in terms of specificity for IVCT, but also to assess the presence of a second MHS trait in families, and the genetic heterogeneity of the disease. Histological analyses revealed the presence of cores in more than 20% of muscle biopsies originating from 242 genotyped and tested MHS patients who did not present with clinical symptoms. This indicates that these patients must be considered as MHS patients with cores, and are clearly differentiated from CCD patients who have been tested positive for MHS.
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Affiliation(s)
- Nicole Monnier
- Laboratoire de Biochimie Génétique et Moléculaire, INSERM U607, Grenoble, France
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30
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Yeh HM, Tsai MC, Su YN, Shen RC, Hwang JJ, Sun WZ, Lai LP. Denaturing High Performance Liquid Chromatography Screening of Ryanodine Receptor Type 1 Gene in Patients with Malignant Hyperthermia in Taiwan and Identification of a Novel Mutation (Y522C). Anesth Analg 2005; 101:1401-1406. [PMID: 16244001 DOI: 10.1213/01.ane.0000180214.74580.39] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
We performed the present study to identify the mutation in patients in Taiwan with malignant hyperthermia (MH). We also test the hypothesis that a denaturing high-performance liquid chromatography (DHPLC) protocol can be used for mutation detection in these patients. We identified five Taiwanese patients with typical clinical presentations of MH after general anesthesia. We also enrolled 50 healthy volunteers. Polymerase chain reaction was used to amplify the ryanodine receptor (RYR1) gene mutation hot spots and DHPLC techniques were used to screen for mutations. Upon detection of a heterozygous elution pattern in DHPLC analysis, DNA sequencing reaction was performed to identify the nucleotide variations. We identified a RYR1 mutation in all 5 patients with MH. There were 4 different mutations in the 5 patients: Tyr522Cys, Arg552Trp, Val2168Met, and Thr2206Arg. Among the 5 patients, 2 unrelated patients had the same Thr2206Arg mutation. Three of the mutations had been reported before, but the Tyr522Cys mutation was novel. None of the MH-related mutations were found in the control group. In conclusion, we identified RYR1 mutations in 5 Taiwanese patients with MH using a DHPLC-based approach. A DHPLC-based genetic test may be developed as a noninvasive and convenient test for MH.
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Affiliation(s)
- Huei-Ming Yeh
- Departments of *Anesthesiology, †Medical Genetics, and ‡Internal Medicine, National Taiwan University Hospital; and §Institute of Pharmacology, National Taiwan University, Taipei, Taiwan
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31
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Abstract
RyRs are large homotetrameric proteins that are approximately 4/5 cytoplasmic and approximately 1/5 transmembrane and luminal in mass. Mutations in RyRs produce human disease and many of these disease-causing mutations are in the cytoplasmic domains. To elucidate the mechanisms of a disease and to develop interventions, it is crucial to determine how the alterations in the cytoplasmic domains communicate with the transmembrane pore of this channel. One of the major activators of all three RyR isoforms is Ca2+ and some of the disease-causing mutations are thought to alter the sensitivity of the channels to Ca2+ activation. This review examines the current state of structural understanding of the RyR channel activation.
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Affiliation(s)
- Susan L Hamilton
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA.
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Bosanac I, Yamazaki H, Matsu-Ura T, Michikawa T, Mikoshiba K, Ikura M. Crystal Structure of the Ligand Binding Suppressor Domain of Type 1 Inositol 1,4,5-Trisphosphate Receptor. Mol Cell 2005; 17:193-203. [PMID: 15664189 DOI: 10.1016/j.molcel.2004.11.047] [Citation(s) in RCA: 130] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2004] [Revised: 11/15/2004] [Accepted: 11/24/2004] [Indexed: 12/31/2022]
Abstract
Binding of inositol 1,4,5-trisphosphate (IP(3)) to the amino-terminal region of IP(3) receptor promotes Ca(2+) release from the endoplasmic reticulum. Within the amino terminus, the first 220 residues directly preceding the IP(3) binding core domain play a key role in IP(3) binding suppression and regulatory protein interaction. Here we present a crystal structure of the suppressor domain of the mouse type 1 IP(3) receptor at 1.8 A. Displaying a shape akin to a hammer, the suppressor region contains a Head subdomain forming the beta-trefoil fold and an Arm subdomain possessing a helix-turn-helix structure. The conserved region on the Head subdomain appeared to interact with the IP(3) binding core domain and is in close proximity to the previously proposed binding sites of Homer, RACK1, calmodulin, and CaBP1. The present study sheds light onto the mechanism underlying the receptor's sensitivity to the ligand and its communication with cellular signaling proteins.
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Affiliation(s)
- Ivan Bosanac
- Division of Molecular and Structural Biology, Ontario Cancer Institute and Department of Medical Biophysics, University of Toronto, 610 University Avenue, Toronto, Ontario, M5G 2M9, Canada
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Abstract
Malignant hyperthermia (MH) is a rare, potentially lethal disorder of skeletal muscle calcium homeostasis characterized by muscle contracture and life-threatening hypermetabolic crisis following exposure to halogenated anesthetics and depolarizing muscle relaxants. Susceptibility to MH results from mutations in calcium channel proteins that mediate excitation-contraction coupling, with the ryanodine receptor calcium release channel (RyR1) representing the major locus. The mode of inheritance appears to be autosomal dominant with variable penetrance. The authors report the death of a 60-year-old white male with a history of low back pain. He had undergone 2 back surgeries previously, the first occurring 10 years prior to his current presentation. Both previous procedures were done under generalized anesthetic with no complications. Recently, he developed stenosis and presented for fusion of vertebrae L3 and L4. The procedure was performed under general anesthetic including sevoflurane, with no intraoperative complications. The anesthesiologist noted that, near the end of the 2-hour procedure, the decedent's CO2 levels were slightly elevated. After the procedure, the decedent was extubated, the temperature probe which had been recording normal values was removed, and he was rolled from ventral to dorsal position. He immediately became hypotensive and bradycardic. Lifesaving interventions were begun. Subsequently, he went into cardiac arrest, at which time the temperature probe was reinserted into the trachea, where it read a body temperature of 109 degrees F. Malignant hyperthermia protocol was initiated, and interventions continued for over 2 hours, at which time they failed. At autopsy, the abdomen contained 1800 mL of blood, and bilateral hematomas were present in the psoas muscles. The authors present this case of clinically apparent malignant hyperthermia, discuss how to approach such a case, the gross and microscopic findings, ancillary studies, and a review of the literature.
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Affiliation(s)
- Lydia R Christiansen
- Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina 29425, USA.
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Bagattin A, Veronese C, Bauce B, Wuyts W, Settimo L, Nava A, Rampazzo A, Danieli GA. Denaturing HPLC-based approach for detecting RYR2 mutations involved in malignant arrhythmias. Clin Chem 2004; 50:1148-55. [PMID: 15131021 DOI: 10.1373/clinchem.2003.030734] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Mutations in the RYR2 gene, which encodes the cardiac ryanodine receptor, have been reported in patients showing either arrhythmogenic right ventricular cardiomyopathy, type 2, or stress-induced polymorphic ventricular tachycardia. Both clinical phenotypes are characterized by a high risk of sudden death. Detection of RYR2 mutations is particularly important because beta-blocker treatment has been shown to be effective in preventing fatal arrhythmias in affected patients. METHODS We used denaturing HPLC (DHPLC) to identify mutations in the human RYR2 gene. Fifty-three single exons, possibly targeted by mutations, were identified by comparison with the distribution of pathogenic mutations of the RYR1 gene, the skeletal muscle counterpart of RYR2. PCR primers for amplification of the entire coding sequence (116 amplicons, corresponding to 105 exons) were tested, and optimal DHPLC conditions were established. DHPLC analysis of critical exons was performed on 22 unrelated patients with effort-induced polymorphic ventricular arrhythmias but lacking a precise diagnosis. RESULTS We identified four novel missense mutations among 22 patients. Their pathogenic role was related to present knowledge of the structure and function of RyR2 protein. CONCLUSIONS Under optimized conditions, DHPLC is a cost-effective, highly sensitive, rapid, and efficient method for mutation screenings. A four-step approach is proposed for mutation screening of the RYR2 gene: (a) DHPLC analysis of 48 critical exons (2-4, 6-15, 17-20, 39-49, 83, 84, 87-97, and 99-105); (b) DNA sequencing of 5 critical exons unsuitable for DHPLC; then, in case of negative results, (c) DHPLC analysis of the remaining 39 exons and (d) DNA sequencing of the last 13 amplicons unsuitable for DHPLC analysis.
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Tammaro A, Bracco A, Cozzolino S, Esposito M, Di Martino A, Savoia G, Zeuli L, Piluso G, Aurino S, Nigro V. Scanning for mutations of the ryanodine receptor (RYR1) gene by denaturing HPLC: detection of three novel malignant hyperthermia alleles. Clin Chem 2003; 49:761-8. [PMID: 12709367 DOI: 10.1373/49.5.761] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Malignant hyperthermia (MH) is a fatal autosomal dominant pharmacogenetic disorder characterized by skeletal muscle hypertonicity that causes a sudden increase in body temperature after exposure to common anesthetic agents. The disease is genetically heterogeneous, with mutations in the gene encoding the skeletal muscle ryanodine receptor (RYR1) at 19q13.1 accounting for up to 80% of the cases. To date, at least 42 RYR1 mutations have been described that cause MH and/or central core disease. Because the RYR1 gene is huge, containing 106 exons, molecular tests have focused on the regions that are more frequently mutated. Thus the causative defect has been identified in only a fraction of families as linked to chromosome 19q, whereas in others it remains undetected. METHODS We used denaturing HPLC (DHPLC) to analyze the RYR1 gene. We set up conditions to scan the 27 exons to identify both known and unknown mutations in critical regions of the protein. For each exon, we analyzed members from 52 families with positive in vitro contracture test results, but without preliminary selection by linkage analysis. RESULTS We identified seven different mutations in 11 MH families. Among them, three were novel MH alleles: Arg44Cys, Arg533Cys, and Val2117Leu. CONCLUSION Because of its sensitivity and speed, DHPLC could be the method of choice for the detection of unknown mutations in the RYR1 gene.
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Affiliation(s)
- Angela Tammaro
- Malignant Hyperthermia Center, AO Cardarelli, via San Giacomo dei Capri 66, 80131 Napoli, Italy
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Urwyler A, Halsall PJ, Mueller C, Robinson R. Ryanodine receptor gene (RYR1) mutations for diagnosing susceptibility to malignant hyperthermia. Acta Anaesthesiol Scand 2003; 47:492; author reply 493. [PMID: 12694155 DOI: 10.1034/j.1399-6576.2003.t01-2-00044.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Rosen MA, Andreae MH, Cameron AG. Nitroglycerin for fetal surgery: fetoscopy and ex utero intrapartum treatment procedure with malignant hyperthermia precautions. Anesth Analg 2003; 96:698-700. [PMID: 12598248 DOI: 10.1213/01.ane.0000049686.20464.3b] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
IMPLICATIONS We report the administration of two anesthetics to a patient potentially at risk for malignant hyperthermia undergoing fetal surgery and an ex utero intrapartum treatment procedure. Management of anesthesia and intraoperative uterine relaxation with i.v. nitroglycerin to avoid volatile anesthetics are discussed.
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Affiliation(s)
- Mark A Rosen
- Department of Anesthesia and Perioperative Care, University of California San Francisco, San Francisco, California
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