Congenital and non-congenital depigmentation.

The hypofunction of melanocytes results in congenital and noncongenital depigmentation. Congenital depigmentation can be further divided into two groups; the first is depigmentation caused by loss of melanization in premelanosomes represented by oculocutaneous albinism; the second group is congenital decrease of melanocytes represented by nevus dipigmentosus. In contrast, acquired progressive depigmentation represented by vitiligo vulgaris and Sutton's leukoderma is characterized by the loss of premelanosome synthesis. The pathogenesis of these three major types of melanogenic defects has been further discussed with the current clinical, biological and immunological view of melanogenesis.