Using transgenic mice to model Ryr1-related myopathy, Boncompagni and colleagues showed that the heterozygous Y522S knock-in (Y522S in human Ryr1 corresponding to Y524S in mouse Ryr1) mice showed the appearance of mitochondrial damage such as swollen, misshapen, and/or disrupted by EM analysis before the core formation at 2 months of age [187]. The gene discussed is RYR1; the disease is myopathy.