Tyrosinase gene mutations in type I (tyrosinase‐deficient) oculocutaneous albinism define two clusters of missense substitutions

RK Tripathi, KM Strunk, LB Giebel… - American journal of …, 1992 - Wiley Online Library
RK Tripathi, KM Strunk, LB Giebel, RG Weleber, RA Spritz
American journal of medical genetics, 1992Wiley Online Library
Type I (tyrosinase‐deficient) oculocutaneous albinism (OCA) results from mutations of the
gene encoding tyrosinase, the enzyme that catalyzes the first 2 steps of melanin pigment
biosynthesis. In type IA (tyrosinase‐negative) OCA tyrosinase enzymatic activity is
completely absent, and in type IB (“yellow”) OCA tyrosinase activity is greatly reduced. Here,
we describe 11 novel mutations of the tyrosinase gene in Caucasian patients with these 2
forms of type I OCA. Type I OCA in Caucasians appears to result from a great variety of …
Abstract
Type I (tyrosinase‐deficient) oculocutaneous albinism (OCA) results from mutations of the gene encoding tyrosinase, the enzyme that catalyzes the first 2 steps of melanin pigment biosynthesis. In type IA (tyrosinase‐negative) OCA tyrosinase enzymatic activity is completely absent, and in type IB (“yellow”) OCA tyrosinase activity is greatly reduced. Here, we describe 11 novel mutations of the tyrosinase gene in Caucasian patients with these 2 forms of type I OCA. Type I OCA in Caucasians appears to result from a great variety of different uncommon alleles. More than 80% of the known missense substitutions associated with type I OCA cluster within 2 relatively small regions of the tyrosinase polypeptide, suggesting that these may correspond to functionally important sites within the enzyme. © 1992 Wiley‐Liss, Inc.
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