Gatenby, PaulTuck, RogerAndrews, CO'Neil, R2015-12-132015-12-130961-2033http://hdl.handle.net/1885/77027Two patients with Down syndrome and the primary antiphospholipid antibody are described. One patient had a vasculopathy similar to that previously described as Moyamoya. Down syndrome is characterized by immune defects including a tendency to autoimmune phenomena. This report extends the scope of these observations and particularly draws out the potential role of antiphospholipid antibodies. Indeed antiphospholipid antibodies may well explain the well-known association of Down syndrome and stroke.Keywords: phospholipid antibody; adult; article; autoimmunity; case report; computer assisted tomography; disease association; Down syndrome; female; human; magnetic resonance angiography; moyamoya disease; nuclear magnetic resonance imaging; priority journal; stro Antiphospholipid syndrome; Down syndrome; Moyamoya; Stroke200310.1191/0961203303lu240cr2015-12-11