Moyamoya syndrome (MMS), an acquired form of MMD, also displays the angiographic pattern of MMD, although it is usually associated with different risk factors such as NF-1, Down syndrome and previous cranial irradiation, among others.4 Associations between NF-1 and vascular disorders are not uncommon, although associations between NF-1 and specific cerebrovascular disorders such as MMS are far less frequent.5,6. The gene discussed is NF1; the disease is Down syndrome.