Any hereditary lymphedema in which the cause of the disease is a mutation in the GJC2 gene. The disease is lymphatic malformation 3 (MONDO_0013278, a Monarch Disease Ontology entry). Also known as: GJC2 hereditary lymphedema, hereditary lymphedema caused by mutation in GJC2, lymphedema, hereditary, 1C, lymphedema, hereditary, type 1C.