Sneddon Syndrome, also known as livedo reticularis-cerebrovascular accident syndrome, is related to antiphospholipid syndrome and cerebrovascular disease, and has symptoms including headache, hemiplegia and seizures. An important gene associated with Sneddon Syndrome is ADA2 (Adenosine Deaminase 2). Affiliated tissues include skin and bone, and related phenotypes are vascular skin abnormality and vertigo