Familial predisposition to tufted angioma: identification of blood and lymphatic vascular components.

Tufted angioma is a rare benign vascular lesion of unknown etiology which mainly affects children under 5 years. It is characterized by nodules or tufts of capillary-sized vessels in the dermis. Here we report the second familial occurrence of tufted angioma, with a mode of inheritance compatible with a monogenic autosomal dominant trait with reduced penetrance. A preliminary investigation was performed to exclude association between the predisposition and certain candidate genes including KDR (kinase insert domain receptor), TEK (TEK tyrosine kinase endothelial), ACVRL1 (activin receptor-like kinase 1), ENG (endoglin) and FLT4 (fms-like tyrosine kinase 4). KDR, ENG and FLT4 were all compatible with linkage, with haplotypes being shared between three affected individuals and the one obligate carrier available for testing. TEK and ACVRL1 could essentially be excluded. Finally, we provide definitive evidence for the existence of both blood and lymphatic vascular elements in the lesion.