Tripathi R K, Strunk K M, Giebel L B, Weleber R G, Spritz R A
Department of Medical Genetics, University of Wisconsin, Madison.
Am J Med Genet. 1992 Jul 15;43(5):865-71. doi: 10.1002/ajmg.1320430523.
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.
I型（酪氨酸酶缺乏型）眼皮肤白化病（OCA）是由编码酪氨酸酶的基因突变引起的，酪氨酸酶是催化黑色素生物合成前两步的酶。在IA型（酪氨酸酶阴性）OCA中，酪氨酸酶的酶活性完全缺失，而在IB型（“黄色”）OCA中，酪氨酸酶活性大大降低。在此，我们描述了11例患有这两种I型OCA的白种人患者酪氨酸酶基因的新突变。白种人中的I型OCA似乎是由多种不同的罕见等位基因引起的。与I型OCA相关的已知错义替代中，超过80%聚集在酪氨酸酶多肽的两个相对较小的区域内，这表明这些区域可能对应于该酶内功能重要的位点。
