CCBE1 and primary lymphedema: Mutations in CCBE1 were identified in human patients with Hennekam syndrome (HS), a rare autosomal recessive disorder of lymphatic development that presents a wide variety of symptoms including primary lymphedema, and heart defects (Van Balkom et al., 2002; Alders et al., 2009; Connell et al., 2010; Connell et al., 2012; Alders et al., 2013; Shah et al., 2013).