一个黏多糖贮积症Ⅱ型家系的IDS基因致病变异特征分析  

Characterization of an IDS pathogenic variant in a family with mucopolysaccharidosis typeⅡ

作　　者：于函菲 秦倩 吴杰[1] 贾学渊 计薇 张学龙 徐丽丹 董科显 关荣伟 王浩[2] 孙文靖 Yu Hanfei;Qin Qian;Wu Jie;Jia Xueyuan;Ji Wei;Zhang Xuelong;Xu Lidan;Dong Kexian;Guan Rongwei;Wang Hao;Sun Wenjing(Key Laboratory of Preservation of Human Genetic Resources and Disease Control in China(Harbin Medical University),Ministry of Education Laboratory of Medical Genetics,Harbin Medical University,Harbin 150081,China;Department of Hepatopancreatobiliary Surgery,Second Affiliated Hospital of Harbin Medical University,Harbin 150086,China)

机构地区：[1]中国遗传资源保护与疾病防控教育部重点实验室(哈尔滨医科大学),哈尔滨医科大学医学遗传学研究室,150081 [2]哈尔滨医科大学附属第二医院胆道胰腺外科,150086

出　　处：《中华内分泌代谢杂志》2023年第4期345-352,共8页Chinese Journal of Endocrinology and Metabolism

基　　金：长江学者和创新团队发展计划项目(IRT1230)。

摘　　要：目的鉴定1个黏多糖贮积症Ⅱ型(mucopolysaccharidosis typeⅡ,MPSⅡ)家系的遗传变异,并对变异位点艾杜糖醛酸-2-硫酸酯酶(IDS):c.323A>C进行功能学研究。方法收集中国北方地区1个五代83名个体的MPSⅡ家系,其中包括4例患者。通过尿液黏多糖、Alder-Reilly小体检测对该病进行辅助诊断,并对核心家系成员进行IDS酶活性检测;通过对MPSⅡ家系患者进行全外显子组测序及生物信息学分析,筛选出该家系候选变异位点,并通过PCR-Sanger测序进一步确定变异位点。最后,针对致病基因变异位点,将野生型IDS过表达质粒(pCMV-hIDS-WT)及携带突变位点的IDS过表达质粒(pCMV-hIDS-c.323A>C)分别转染COS-7细胞,进行IDS酶活性检测。结果先证者(Ⅳ3)及Ⅳ4经尿液黏多糖、Alder-Reilly小体及IDS酶活性检测诊断为MPSⅡ,Ⅳ3、Ⅳ4、Ⅲ19和Ⅲ32基因检测均携带IDS:c.323A>C错义变异,确诊为MPSⅡ患者;并有8名个体为IDS:c.323A>C错义变异携带者,Ⅱ2、Ⅱ4、Ⅱ8、Ⅱ12、Ⅱ14、Ⅲ5、Ⅲ7、Ⅳ14排除MPSⅡ诊断。COS-7细胞体外实验结果显示,该错义变异可导致IDS酶活性显著降低。结论本研究确定了IDS:c.323A>C:p.Y108S在体内和体外均可导致IDS酶活性显著降低,判定为MPSⅡ的致病性变异。Objective To identify the genetic variation in a mucopolysaccharidosis typeⅡ(MPSⅡ)family,and conduct a functional study of iduronate-2-sulfatase(IDS):c.323A>C.Methods A five-generation MPSⅡfamily of 83 individuals including 4 patients from northern China was collected.Urine mucopolysaccharide and Alder-Reilly body were tested to assist the clinical diagnosis of MPSⅡ.IDS enzyme activity was detected on core family members.By the whole exome sequencing of a MPSⅡpatient in this family and bioinformatics analysis,the variant was screened and further identified by PCR-Sanger sequencing.Finally,to validate the function of the variant in vitro,the wild-type IDS overexpression plasmid(pCMV-hIDS-WT)and the IDS overexpression plasmid carrying the mutation site(pCMV-hIDS-c.323A>C)were transfected into COS-7 cells and the IDS activity was detected.Results The proband(Ⅳ3)andⅣ4 were diagnosed as MPSⅡby urine mucopolysaccharide,Alder-Reilly body,and IDS enzyme activity tests.Ⅳ3,Ⅳ4,Ⅲ19,andⅢ32 were determined to carry IDS:c.323A>C missense variant through the whole-exome sequencing,and diagnosed as MPSⅡ.Meanwhile,Ⅱ2,Ⅱ4,Ⅱ8,Ⅱ12,Ⅱ14,Ⅲ5,Ⅲ7,Ⅳ14 in the MPSⅡfamily carried IDS:c.323A>C missense variant,and were excluded as MPSⅡ.The in vitro experiment in COS-7 cells showed that the missense mutation led to a significant decrease in IDS enzyme activity.Conclusion The variant IDS:c.323A>C:p.Y108S significantly decreases the activity of IDS enzyme in vivo and in vitro,and it is identified as a pathogenic variant for MPSⅡ.

关 键 词：黏多糖贮积症Ⅱ型 艾杜糖醛酸-2-硫酸酯酶基因 全外显子组测序 c.323A>C:p.Y108S变异 

分 类 号：R589[医药卫生—内分泌]