Rhabdomyosarcoma Associated with Core Myopathy/Malignant Hyperthermia: Combined Effect of Germline Variants in RYR1 and ASPSCR1 May Play a Role

Rhabdomyosarcomas have been described in association with thyroid disease, dermatomyositis, Duchenne muscular dystrophy, and dystrophy models but not patients ryanodine receptor-1 gene (RYR1) pathogenic variants. We here an 18-year-old male who reported a cervical nodule. Magnetic resonance images revealed mass the ethmoidal sinus corresponding to rhabdomyosarcoma. As his father died from malignant hyperthermia (MH), vitro contracture test was conducted positive for MH susceptibility. Muscle histopathological analysis biopsy showed presence of cores. Molecular using NGS sequencing identified germline variants RYR1 ASPSCR1 (alveolar soft part sarcoma) genes. This report expands spectrum diseases associated rhabdomyosarcomas possible differential diagnosis tissue tumors