Centronuclear myopathy due to a heterozygous de novo dominant mutation in the skeletal muscle ryanodine receptor (RYR1) gene has to date been reported in only one case [82], with clinical features comprising extraocular involvement, generalized weakness, moderate bulbar and respiratory impairment similar to multi-minicore disease (MmD), due to recessive mutations in the RYR1 gene [83,84]. Here, RYR1 is linked to centronuclear myopathy.