The RYR1 gene provides instructions for making a protein called ryanodine receptor 1 (also called the RYR1 channel). This protein is part of a group of related proteins called ryanodine receptors, which form channels that, when turned on (activated), release positively charged calcium atoms (ions) from storage within cells. RYR1 channels play a critical role in muscles used for movement (skeletal muscles).~For the body to move normally, skeletal muscles must tense (contract) and relax in a coordinated way. Muscle contractions are triggered by an increase in the concentration of calcium ions inside muscle cells.~RYR1 channels are located in the membrane surrounding a structure in muscle cells called the sarcoplasmic reticulum. This structure stores calcium ions when muscles are at rest. In response to certain signals, the RYR1 channel releases calcium ions from the sarcoplasmic reticulum into the cell fluid. The resulting increase in calcium ion concentration in muscle cells stimulates muscles to contract, allowing the body to move. The process by which electrical signals trigger muscle contraction is called excitation-contraction (E-C) coupling.