Noonan syndrome is characterized by facial dysmorphology, congenital heart disease and growth failure. Although it is also accompanied by deranged lymph-vessel formation, protein-losing enteropathy (PLE) with Noonan syndrome is rarely reported. We report clinical information about a boy with Noonan syndrome and late-onset Lymphedema and PLE after standing for long periods of time during athletic practice sessions. The boy recovered from Lymphedema and PLE after administration of 2.5 g of albumin followed by resting and raising his legs. They did not recur after he began walking again. Standing for long periods of time congested the lymph stream at the abdominal lymph vessel, whose formation is frequently disturbed in Noonan syndrome, and the increased pressure caused Lymphedema and PLE. PLE is one of the clinical manifestations of Noonan syndrome.
