Congenital and genetic disorders associated with hypopigmentation

The distinctive clinical and pathologic features of congenital and genetic disorders associated with hypopigmentation are reviewed. Disorders in which focal hypopigmentation are seen include piebaldism, Waardenburg syndrome, and hypomelanosis of Ito. A number of syndromes resulting in premature graying of the hair, including those associated with premature aging, are also discussed. Diffuse hypopigmentation is a hallmark of disorders grouped under the rubric of oculocutaneous albinism, including type I and II albinism, the Hermansky-Pudlak, Chediak-Higashi, and Griscelli-Pruniéras syndromes. Recent advances in the molecular and genetic aspects of many of the aforementioned disorders are also discussed.