ABSTRACT
Albinism is the general term used to describe a series of congenital and inherited diseases characterized by an abnormally low amount of melanin in normally pigmented tissues and affecting the skin, hair, and eyes (oculocutaneous albinism) or the eyes alone (ocular albinism). Several authors qualify the definition by including nystagmus, photophobia, and reduced visual acuity, using the term albinoidism if hypomelanosis occurs without nystagmus (1). Because of its striking appearance, the oculocutaneous form of albinism, since the dawn of history, has been known to exist in humans and in much of the animal kingdom. Only recently, however, has the complexity of the clinical, genetic, pathologic, and pathophysiologic aspects of the subject been known. At least 10 different types of oculocutaneous albinism, and at least four different types of ocular albinism are now recognizable. The number of genes involved in human albinism is even greater. In addition to the genes associated with oculocutaneous and ocular albinisms, seven genes are involved in the Hermansky-Pudlak syndrome and seven genes in the Waardenburg syndromes. This is a minimal total of 24 genes (2). However, in animals a greater number of genes are responsible for pigmentation, and a whole book has been written on the coat color of mammals (3).
