TYR and oculocutaneous albinism type 1: Human tyrosinase is a type 1 trans-membrane and copper-containing glycoenzyme that catalyzes the rate-limiting step of melanin pigment production in melanosomes.1,2 Mutations in the tyrosinase gene (TYR) can lead to oculocutaneous albinism Type 1 (OCA1), an autosomal recessive disease.