These include disorders of DNA replication/repair functions (Bloom, Werner, Rothmund-Thomson and Muir-Torre syndromes), genodermatoses affecting the folliculo-sebaceus unit (Brooke-Spiegler, Schöpf-Schulz-Passarge and Cowden syndromes), immune response (cartilage-hair hypoplasia and epidermodysplasia verruciformis) and melanin biosynthesis (oculocutaneous albinism and Hermansky-Pudlak syndrome), and some epidermal nevus syndromes.