RNF213 and stroke disorder: The specific association between RNF213 gene variants and pediatric MMD and stroke has been described previously, both in children heterozygous or homozygous for the founder East‐Asian p.(Arg4810Lys) variant as well as in children with rare, de novo variants (Guey et al., 2017; Ito et al., 2015; Miyatake et al., 2012; Zhang et al., 2019).