RNF213 and multiminicore myopathy: The c.14576G>A polymorphism in RNF213 was identified in 95% of familial MMD cases and 79% of sporadic MMD cases.37,38 The c.14576G>A polymorphism in RNF213 is located in neither the AAA+ATPase domain nor the RING finger ubiquitin ligase domain [42–44].