一个糖原累积病Ⅱ型家系的酸性-α-葡萄糖苷酶及其产前基因诊断  

Application of enzyme assay and gene analysis in the prenatal diagnosis for a family with glycogen storage disease typeⅡ

作　　者：曾敏慧[1] 邱文娟[1] 顾学范[1] 王瑜[1] 周建德[1] 叶军[1] 韩连书[1] 张惠文[1] 

机构地区：[1]上海交通大学医学院附属新华医院上海市儿科医学研究所内分泌遗传代谢病研究室,200092

出　　处：《中华医学遗传学杂志》2011年第3期261-265,共5页Chinese Journal of Medical Genetics

基　　金：国家自然科学基金（30973216）;上海市教委科研创新项目（09YZ99）

摘　　要：目的为1个糖原累积病Ⅱ型（glycogen storage diseasetypeⅡ，GSDⅡ）家系进行酶学和产前基因诊断。方法用酸性-α-葡萄糖苷酶（acid—alpha-glucosidase，GAA）特异性水解荧光底物4甲基伞型酮-α-D-Ptt喃葡萄糖苷（4-methylumbelliferyl-α-D-glucopyranoside，4-MUG）和阿卡波糖抑制其同工酶的方法检测外周血白细胞和羊水细胞GAA酶活性，聚合酶链反应扩增GAA基因外显子编码区序列，直接测序分析GAA基因突变情况。结果先证者外周血白细胞与胎儿羊水细胞GAA酶活性均明显低于正常参考值范围，分别为正常对照平均值的12．3％和1．1％。先证者和胎儿均携带新无义突变P．W738X和已报道的无义突变P．E888X；先证者、母亲和胎儿均携带假性缺陷等位基因[c．1726G〉A；c．2065G〉A]。结论通过GAA酶活性检测结合GAA基因分析对1个GSDⅡ家系进行了产前诊断。由于假性缺陷等位基因可引起GAA酶活性降低，故GAA基因分析应作为亚洲人群GSDⅡ产前诊断的常规手段。Objective To carry out prenatal diagnosis for a glycogen storage disease type Ⅱ （GSD Ⅱ ） affected family. Methods The acid-α-glucosidase （GAA） activity was measured in whole leukocytes and cultured amniocytes with 4-methylumbelliferyl-α-D-glucopyranoside as substrate and with acarbose as inhibitor. The coding regions of GAA gene were amplified by polymerase chain reaction and analyzed by direct DNA sequencing. Results The proband and the fetus had low GAA activity （12.3 %and 1.1%of the average normal range, respectlvely）. Mutation analysis of the GAA gene revealed a novel nonsense mutation p. W738X and a reported nonsense mutation p. E888X in both the proband and the fetus; the reported pseudodeficiency allele c. [1726G〉A; 2065G〉A] was found in the proband, the mother and the fetus. Conclusion The prohand and the fetus were both GSD U affected. A combination of GAA activity analysis and mutation analysis is efficient for the prenatal diagnosis of GSDⅡ, Mutation analysis should be a routine method in the prenatal diagnosis of GSD Ⅱ in Asian population, where pseudodeficlency allele can cause low GAA activity in normal individuals which is relatively common in Asian.

关 键 词：糖原累积病Ⅱ型 酸性α-葡萄糖苷酶 产前诊断 假性缺陷等位基因 

分 类 号：R714.5[医药卫生—妇产科学]