Yoshida K, Yanagisawa N
Department of Medicine (Neurology), Shinshu University School of Medicine.
Nihon Rinsho. 1993 Sep;51(9):2269-75.
Recent advances in the molecular study of beta-galactosidase deficiency (GM1-gangliosidosis and Morquio syndrome type B) are reviewed. Until now, 14 different mutations have been found in the beta-galactosidase gene in patients with this disorder. Gene mutations are heterogeneous, but common and specific mutations have been identified for three types of protracted clinical course; 51Ile-->Thr mutation for Japanese adult/chronic GM1-gangliosidosis, 201Arg-->Cys for Japanese late infantile/juvenile GM1-gangliosidosis and 273Trp-->Leu for Caucasian Morquio syndrome type B. These phenotype-specific mutant genes produce mutant proteins with significant residual enzyme activity, whereas mutant proteins associated with infantile GM1-gangliosidosis patients show complete loss of enzyme activity. The phenotypic variations of this disorder may be related to different mode of intracellular processing and turnover of mutant enzyme proteins.
本文综述了β-半乳糖苷酶缺乏症（GM1神经节苷脂贮积症和B型莫尔基奥综合征）分子研究的最新进展。迄今为止，已在患有这种疾病的患者的β-半乳糖苷酶基因中发现了14种不同的突变。基因突变具有异质性，但已针对三种类型的迁延性临床病程鉴定出常见和特异性突变；日本成人/慢性GM1神经节苷脂贮积症的51Ile→Thr突变、日本晚发性婴儿/青少年GM1神经节苷脂贮积症的201Arg→Cys突变和白种人B型莫尔基奥综合征的273Trp→Leu突变。这些表型特异性突变基因产生具有显著残余酶活性的突变蛋白，而与婴儿型GM1神经节苷脂贮积症患者相关的突变蛋白则显示酶活性完全丧失。这种疾病的表型变异可能与突变酶蛋白的细胞内加工和周转方式不同有关。
