A patient with a ryanodine receptor 1 (RYR1) gene mutation and severe early-onset scoliosis associated with congenital myopathy and malignant hyperthermia: a case report

Abstract

Introduction: Malignant hyperthermia (MH) is a muscle disorder with an autosomal dominant inheritance that presents mainly during general anesthesia. Patients with congenital myopathy, including central core disease, often have a risk of developing MH. Mutations in the ryanodine receptor (RYR1) gene are a major cause of congenital myopathy and MH.

Case Report: A female patient with an RYR1 mutation had early-onset scoliosis due to congenital myopathy. At 10 years old, her thoracic spinal curvature had progressed to 66° and her lumbar curvature to 79°. Repeating growth-friendly treatments such as growing rod surgery increases the patient's risk of developing MH during the growth period. The patient was twice placed in a Risser-Cotrel cast under total intravenous anesthesia (TIVA). Serial casting delayed surgical treatment for about 2 years. Finally, at 12 years old, she underwent scoliosis surgery using spinal instrumentation. Despite 3 episodes of TIVA, she has never suffered from MH. At 2 years postoperatively, her thoracic spinal curvature improved to 29° and lumbar curvature to 31° without a crankshaft phenomenon.

Conclusions: Scoliosis surgery for a patient with congenital myopathy was successfully managed using TIVA. Despite congenital myopathy in patients with an RYR1 mutation, intravenous anesthetics may not be as commonly associated with the onset of MH as thought.