The replacement of this glycine by a polar residue has been associated with skin disease in several connexins (Cx26 p.G12R in relation to KID, Cx31 p.G12R, p.G12D Cx30.3, p.G12D in EKV, and Cx30 p.G11R in Clouston syndrome) [59, 65-68]. Here, GJB4 is linked to Clouston syndrome.