Pleiotropy versus heterogeneity in Proteus syndrome

To the Editor.— I read with interest the article by Costa et al1 on a "new" clinical feature in Proteus syndrome. It appears that there is a lot to be learned about hamartoses and localized growth deficiency. This is apparent from the article and the existence of children with multiple hamartomas defying the current classification of these unique conditions. The classification includes the "new" Bannayan, Zonana, and Riley-Smith syndromes, 2-4 in addition to the "old" neurofibromatosis, tuberous sclerosis, Klippel -Trenaunay -Weber, and Cowden syndromes.