MUTATIONS OF THE TYROSINASE GENE IN INDO-PAKISTANI PATIENTS WITH TYPE-I (TYROSINASE-DEFICIENT) OCULOCUTANEOUS ALBINISM (OCA)

Oculocutaneous albinism (OCA) is a group of autosomal recessive disord ers characterized by deficient synthesis of melanin pigment. Type I (t yrosinase-deficient) OCA results from mutations of the tyrosinase gene (TYR gene) encoding tyrosinase, the enzyme that catalyzes the first t wo steps of melanin biosynthesis. Mutations of the TYR gene have been identified in a large number of patients, most of Caucasian ethnic ori gin, with various forms of type I OCA. Here, we present an analysis of the TYR gene in eight Indo-Pakistani patients with type I OCA. We des cribe four novel TYR gene mutations and a fifth mutation previously ob served in a Caucasian patient.