Update on RYR1-related myopathies.

PURPOSE OF REVIEW: RYR1-related myopathy (RYR1-RM) is a group of myopathies caused by mutations in the RYR1 gene, which encodes the ryanodine receptor 1 (RYR1). This review discusses recent advances in the clinical features, pathology, pathogenesis, and therapeutics of RYR1-RM.

RECENT FINDINGS: Although treatments such as salbutamol, pyridostigmine, and N-acetylcysteine have been explored as potential therapies for RYR1-RM, none have been conclusively proven to be effective. However, recent clinical trials of Rycal ARM210 in patients with RYR1-RM have shown promising results, including reduced fatigue and improved proximal muscle strength.Recent advances in three-dimensional structural analysis of RYR1 channels, facilitated by cryo-electron microscopy (cryo-EM), have elucidated the distinct molecular mechanisms underlying RYR1 functionality. Additionally, high-throughput screening methods, including FRET-based and endoplasmic reticulum Ca2+-based assays, have been successful in identifying potential candidates for the treatment of RYR1-RM.

SUMMARY: Recent advances in clinical and pathological understanding have provided new insights into RYR1-RM. Novel pathomechanisms elucidated by cryo-EM and rapid screening methods have led to the identification of several promising drug candidates. We are hopeful about the potential of Rycal, other new drugs, and gene therapy, offering a promising outlook for the future.