Rapid Progression of Unilateral Moyamoya Disease in a Patient with a Family History and an <b><i>RNF213</i></b> Risk Variant

vealed two haplotypes carrying p.R4810K: allele A 2 , which is common among patients with MMD, and allele A 1 , which is rare among patients with MMD [6] . The patient inherited an A 1 allele for p.R4810K ( fig. 1 d). On the other hand, her elder and younger sisters inherited an A 2 allele from their mother for p.R4810K, and no arterial stenosis was identified in either the initial or annual follow-up MRI examinations. Ethical approval for this study was given by the Institutional Review Board and Ethics Committee of the Kyoto University School of Medicine, Kyoto University, Japan.