CHUK and van der Woude syndrome: These syndromes arise as the result of mutations in IRF6 (Van der Woude syndrome and popliteal pterygium syndrome); GRHL3 (a subset of IRF6‐negative cases of Van der Woude syndrome); RIPK4 (Bartsocas Papas syndrome); and IKKα (cocoon syndrome; Bartsocas Papas syndrome) (Kalay et al., 2012; Kondo et al., 2002; Lahtela et al., 2010; Leslie et al., 2015; Mitchell et al., 2012; Peyrard‐Janvid et al., 2014).