Ryanodine receptor 1-related disorder presenting with malignant hyperthermia

Yeniay Süt N., Yıldırım M., Yüksel M. F., Kartal A. T., Bektaş Ö., Teber S.

15th Congress of the European Paediatric Neurology Society (EPNS), Praha, Çek Cumhuriyeti, 20 - 24 Haziran 2023, ss.627

  • Yayın Türü: Bildiri / Özet Bildiri
  • Basıldığı Şehir: Praha
  • Basıldığı Ülke: Çek Cumhuriyeti
  • Sayfa Sayıları: ss.627
  • Ankara Üniversitesi Adresli: Evet

Özet

: Introduction Malignant hyperthermia is a hypermetabolic reaction involving fever and muscle rigidity due to continued muscle contraction. It usually occurs with volatile anesthetic exposure in individuals with malignant hyperthermia susceptible. We present a 9-year-old girl with a ryanodine receptor 1 (RYR1) gene mutation who developed malignant hyperthermia due to anesthetic exposure. Case Report A previously healthy 9-year-old girl presented with generalized tonic-clonic seizures and fever after receiving anesthetic agents for appendicitis. After she was diagnosed with malignant hyperthermia, 2.5 mg/kg/dose of dantrolene sodium was administered intravenously three times and the symptoms improved. She was born after uneventful pregnancy and delivery, with a non-consanguineous marriage of her parents. She had no family history in terms of neuromuscular disease. Neurological examination was normal except for mild scoliosis. Serum value of creatine kinase ranged from 800 to 3000 U/L (normal range up to 170 U/L). Transthoracic echocardiography was normal. Electroneuromyography showed the presence of a short-term, low amplitude, polyphasic motor unit action potential (MUAP) consistent with myopathic involvement. The next-generation sequencing test showed a heterozygous mutation of the RYR1 gene [c.7304G>A; (p.R2435H)]. Thus, she was diagnosed with malignant hyperthermia associated with ryanodine receptor 1-related disorder. Conclusion RYR1 variants may lead to dysfunctional RYR1-mediated calcium release, resulting in susceptibility to malignant hyperthermia. RYR1-related disorders are characterized by delayed motor milestones, scoliosis, ophthalmoplegia, contractures, and respiratory insufficiency. Familiarity with the wide spectrum of RYR1 is of great importance to all pediatric neurologists and anesthesiologists in recognizing patients at risk for malignant hyperthermia.