Dysfunction of AP complexes has been implicated in a variety of inherited disorders, including: MEDNIK (mental retardation, enteropathy, deafness, peripheral neuropathy, ichthyosis and keratodermia) syndrome, Fried syndrome, HPS (Hermansky–Pudlak syndrome) and HSP (hereditary spastic paraplegia). The gene discussed is DHCR7-DT; the disease is ichthyosis.