COL4A1 and muscular dystrophy-dystroglycanopathy, type A: Mutations in COL4A1 cause a wide spectrum of autosomal dominant disorders including porencephaly, brain small-vessel disease with hemorrhage, leukoencephalopathy, hereditary angiopathy with nephropathy, aneurysms and muscle cramp (HANAC) syndrome, and Walker–Warburg syndrome [20].