Locations and effects of ryanodine receptor type 1 mutations. A: Amino acid (AS) sequence of the ryanodine receptor type 1 (RyR1) from the n-terminal end to the c-terminal end. Most of the mutations found in this study are located in one of the three hot spots: MH/CCD region 1: AS 35 to 614; MH/CCD region 2: AS 2163 to 2458; MH/CCD region 3: AS 4664 to 5020. B: Clinical grading scale (mean) for each RyR1 mutation in regard of the location of the patients mutation within the gene. C: Box plot showing clinical grading scales (CGS) depending on the location of the ryanodine receptor type 1 mutation. Boxes delineate the inter-quartile range (25% to 75%), black horizontal lines within the boxes show median values, whiskers indicate ranges and white squares represent mean values. Mann–Whitney U-test reveals significantly higher CGS of MH/CCD region 1, 2 and 3 compared to other regions of the protein.