LORICRIN and Palmoplantar keratoderma: Loricrin keratoderma (LK [MIM: 604117]) is a rare autosomal dominant skin disorder that results from gain-of-function mutations in LOR (MIM: 152445), which encodes loricrin, on 1q21.3 (Ishida-Yamamoto et al, 1997; Ishida-Yamamoto, 2003).