ABCA12 and Pseudoxanthoma elasticum: Genetic alterations in several of these genes have been linked to congenital keratinization disorders such as Pseudoxanthoma Elasticum (causal mutations in ABCC6), Harlequin ichthyosis (ABCA12) and lamellar ichthyosis (ABCA12), a form of ichthyosis characterized by skin desquamation over the whole body.