Aagenaes syndrome, also called cholestasis-lymphedema syndrome (CHLS), is a form of idiopathic familial intrahepatic cholestasis associated with lymphedema of the lower extremities. The syndrome is named after the Norwegian pediatrician Oyestein Aagenaes, who described the syndrome in 1968. In those affected, cholestasis is severe during neonatal period and lessens during early childhood, eventually becoming episodic. When cholestatic, these patients need a fat reduced diet. The presence of lymphedema is likely the predisposing factor for development of recurrent infections in such patients.

The condition is particularly frequent in the southern most part of Norway and the gene frequency is estimated to be about 3%. In general, the condition is found in patients from other parts of Europe and the US, but more than half of the cases are of Norwegian origin.

CHLS is the only known form of hereditary lymphedema associated with cholestasis. A locus, LCS1, has recently been mapped to chromosome 15q in families having the disease.