Knowing that the variant allele of RNF213 appeared more frequently in individuals with syndromic forms of MMD than in the control group (our unpublished data), we assume that functional loss of RNF213 may contribute to the development of MMD even in the presence of other genetic causes or environmental risk factors, such as varicella zoster virus infection. This evidence concerns the gene RNF213 and multiminicore myopathy.