Hennekam lymphangiectasia-lymphedema syndrome 2 (MONDO_0014454, a Monarch Disease Ontology id) is any Hennekam syndrome in which the cause of the disease is a mutation in the FAT4 gene. Also known as: FAT4 Hennekam syndrome, Hennekam lymphangiectasia-lymphedema syndrome type 2, Hennekam syndrome caused by mutation in FAT4.