{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,22]],"date-time":"2026-08-22T04:28:11Z","timestamp":1787372891455,"version":"build-2736575974"},"reference-count":25,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2026,8,20]],"date-time":"2026-08-20T00:00:00Z","timestamp":1787184000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001691","name":"Japan Society for the Promotion of Science","doi-asserted-by":"crossref","award":["22K09070"],"award-info":[{"award-number":["22K09070"]}],"id":[{"id":"10.13039\/501100001691","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/501100001691","name":"Japan Society for the Promotion of Science","doi-asserted-by":"crossref","award":["22K16602"],"award-info":[{"award-number":["22K16602"]}],"id":[{"id":"10.13039\/501100001691","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/501100001691","name":"Japan Society for the Promotion of Science","doi-asserted-by":"crossref","award":["23K08382"],"award-info":[{"award-number":["23K08382"]}],"id":[{"id":"10.13039\/501100001691","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/501100001691","name":"Japan Society for the Promotion of Science","doi-asserted-by":"crossref","award":["23K08332"],"award-info":[{"award-number":["23K08332"]}],"id":[{"id":"10.13039\/501100001691","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/501100001691","name":"Japan Society for the Promotion of Science","doi-asserted-by":"crossref","award":["25K12146"],"award-info":[{"award-number":["25K12146"]}],"id":[{"id":"10.13039\/501100001691","id-type":"DOI","asserted-by":"crossref"}]},{"name":"Tsuchiya Memorial Medical Foundation"},{"id":[{"id":"https:\/\/ror.org\/011r7vr09","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Genes"],"abstract":"<jats:p>Background\/Objectives: Malignant hyperthermia (MH) is a life-threatening pharmacogenetic disorder of skeletal muscle primarily associated with pathogenic variants in RYR1; however, a substantial proportion of MH-susceptible individuals lack identifiable variants in known genes. This study aimed to identify novel genetic contributors in Ca2+-induced Ca2+ release (CICR)-positive patients without RYR1 variants and to evaluate their functional relevance. Methods: Among 29 CICR-positive individuals without pathogenic variants identified by gene panel testing, five patients underwent whole-exome sequencing (WES). In one family, heterozygous variants in ANO5 (p.Arg547Gln) and ORAI3 (p.Arg287Cys) were identified. To evaluate their functional significance, intracellular Ca2+ dynamics were analyzed in primary myotubes derived from Case 165, an affected individual carrying both variants, and compared with those from CICR-negative controls and CICR-positive patients harboring RYR1 variants. Results: Myotubes derived from Case 165 demonstrated enhanced sensitivity to caffeine and 4-chloro-m-cresol, elevated resting intracellular Ca2+ levels, and greater Ca2+ reduction under Ca2+-free conditions compared with CICR-negative controls, resembling the phenotype observed in the RYR1 variant group. In contrast, dantrolene-induced Ca2+ reduction was significantly greater only in the RYR1 variant group. Conclusions: These findings suggest that ANO5 and ORAI3 variants may contribute to abnormal Ca2+ regulation in MH-susceptible individuals without RYR1 mutations and highlight the importance of combining genomic analysis with functional validation to identify novel genetic contributors to MH susceptibility.<\/jats:p>","DOI":"10.3390\/genes17080980","type":"journal-article","created":{"date-parts":[[2026,8,20]],"date-time":"2026-08-20T09:48:31Z","timestamp":1787219311000},"page":"980","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Functional Characterization of Patient-Derived Myotubes Carrying ANO5 and ORAI3 Variants in RYR1-Negative Malignant Hyperthermia Susceptibility"],"prefix":"10.3390","volume":"17","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-1375-5344","authenticated-orcid":false,"given":"Hirotsugu","family":"Miyoshi","sequence":"first","affiliation":[{"name":"Department of Anesthesiology and Critical Care, Hiroshima University, Hiroshima 734-8551, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4771-9867","authenticated-orcid":false,"given":"Sachiko","family":"Otsuki","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology and Critical Care, Hiroshima University, Hiroshima 734-8551, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4449-1695","authenticated-orcid":false,"given":"Kenshiro","family":"Kido","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology and Critical Care, Hiroshima University, Hiroshima 734-8551, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0005-7077-249X","authenticated-orcid":false,"given":"Ayako","family":"Sumii","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology and Critical Care, Hiroshima University, Hiroshima 734-8551, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7277-1248","authenticated-orcid":false,"given":"Tsuyoshi","family":"Ikeda","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology and Critical Care, Hiroshima University, Hiroshima 734-8551, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0000-6142-7700","authenticated-orcid":false,"given":"Guoqiang","family":"Xia","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology and Critical Care, Hiroshima University, Hiroshima 734-8551, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yuko","family":"Noda","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology and Critical Care, Hiroshima University, Hiroshima 734-8551, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0008-9957-2899","authenticated-orcid":false,"given":"Tomomi","family":"Ishii","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology and Critical Care, Hiroshima University, Hiroshima 734-8551, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9827-1404","authenticated-orcid":false,"given":"Satoshi","family":"Kamiya","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology and Critical Care, Hiroshima University, Hiroshima 734-8551, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Soshi","family":"Narasaki","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology and Critical Care, Hiroshima University, Hiroshima 734-8551, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0077-3284","authenticated-orcid":false,"given":"Huei-Ming","family":"Yeh","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology, National Taiwan University Hospital, Taipei 100, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5640-3074","authenticated-orcid":false,"given":"Pei-Lung","family":"Chen","sequence":"additional","affiliation":[{"name":"Graduate Institute of Medical Genomics and Proteomics, National Taiwan University, Taipei 100, Taiwan"},{"name":"Departments of Medical Genetics and Internal Medicine, National Taiwan University Hospital, Taipei 100, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yasuko","family":"Ichihara","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology, Kikkoman General Hospital, Chiba 278-0005, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7255-852X","authenticated-orcid":false,"given":"Keiko","family":"Mukaida","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology and Critical Care, Hiroshima University, Hiroshima 734-8551, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1997-082X","authenticated-orcid":false,"given":"Yasuo M.","family":"Tsutsumi","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology and Critical Care, Hiroshima University, Hiroshima 734-8551, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"93","DOI":"10.1186\/s13023-015-0310-1","article-title":"Malignant hyperthermia: A review","volume":"10","author":"Rosenberg","year":"2015","journal-title":"Orphanet J. 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