Klippel-Trenaunay syndrome and Sturge-Weber syndrome: variations on a theme?

We describe a patient with a complex neurocutaneous syndrome of congenital vascular malformations, abnormalities of brain and bones, and soft tissue hypertrophy of one leg. According to eponymous classification schemes, the patient can be assigned to two different clinical entities. Using the lethal gene theory it is possible to unify these different syndromes and to explain the overlap and diversity of these congenital vascular syndromes. We argue that it is better to describe such vascular malformation syndromes in anatomical/histological or functional terms and map the extent of the disease, rather than name it according to the eponymous classification.