Department of Medical Genetics, University of Wisconsin, Madison 53706, USA.
Type II oculocutaneous albinism (OCA2) is an autosomal recessive disorder in which the biosynthesis of melanin pigment is reduced in the skin, hair, and eyes. OCA2, which results from mutations of the P gene, is the most frequent type of albinism in African and African-American patients. OCA2 is especially frequent in Tanzania, where it occurs with an incidence of approximately 1/1,400. We have identified abnormalities of the P gene in each of 13 unrelated patients with OCA2 from Tanzania. One of these, a deletion of exon 7, is strongly predominant, accounting for approximately 77% of mutant alleles in this group of patients.