Capillary malformation-arteriovenous malformation (CM-AVM) is a vascular disorder that is associated with mutations in the gene RASA1. A small subset of patients harboring this mutation have also been found to exhibit lymphatic abnormalities such as lymphedema in the upper and lower extremities [72,73], chylous ascites [74], chylothorax [74] and swelling with lymphatic vesicles [73]. Here, RASA1 is linked to Chylothorax.