Fig. 1

Moyamoya angiopathy. An identical twin first-born twin sister (II-1), who developed MMD at the age of 36 years, had stenosis in her anterior and middle cerebral arteries bilaterally and underwent surgery. The second-born twin sister (II-2) is represented with a solid quadrant. Magnetic resonance angiography (lower panels) was taken when they were 55 years old. Patient II-2 showed stenosis (arrows). Their mother (I-2) died when she was 71 years old from cerebral infarction. Her niece also developed MMD (II-3). Subjects I-3, II-1, II-2, and II-3 all shared the WT/R4810K genotype. We assumed the carrier status for I-2, I-3, and II-2 in our linkage analysis. Due to the rarity of the disease gene, we assumed that I-2 is a carrier of the MMD-associated gene. This pedigree is simplified from the original pedigree 14 [12]