Albinism and H ermansky‐ P udlak Syndrome

Abstract The term albinism refers to a group of congenital genetic abnormalities resulting from an inability of the pigment cell (melanocyte) to synthesize normal amounts of melanin pigment and is produced by mutations in at least 12 genes. Reduced melanin synthesis in the melanocytes of the skin, hair, and eyes produces oculocutaneous albinism, while a reduction primarily involving the retinal pigment epithelium produces ocular albinism. Hermansky‐Pudlak syndrome includes the triad of oculocutaneous albinism, a mild bleeding diathesis, and a ceroid storage disease affecting primarily the lungs and the gut. Oculocutaneous albinism is the most common inherited disorder of generalized hypopigmentation, with an estimated frequency of 1 in 20,000 in most populations. It has been described in all ethnic groups and in all animal species making it one of the most widely distributed genetic abnormalities in the animal kingdom. Ocular albinism is less common with an estimated frequency of 1 in 50,000 to 1 in 60,000. It is X‐linked. Hermansky‐Pudlak syndrome is a rare condition in most populations. In the Puerto Rican population, however, two forms are found with type 1 having an estimated frequency of approximately 1 in 1800.