Hennekam lymphangiectasia-lymphedema syndrome (HKLLS) is characterized by congenital lymphedema, lymphangiectasia, unusual facial morphology, and variable intellectual disabilities. Mutations in CCBE1, an extracellular matrix protein essential for the development of the lymphatic vasculature, have been found responsible for the syndrome. As a second cause for HKLLS, the mutations in FAT4 have been described.
