三个石骨症致病基因内的新突变及其基因型-表型  

Three Novel Pathogenic Mutations in Osteopetrosis Genes TCIRG1 and CLCN7 and the Genotype-Phenotype Studies

作　　者：曾好[1] 蒋丹华[1] 陈明晖[2] 黄轩[3] 刘瑞虹[1] 郭鹏[4] 王一鸣[1,5] 方群[3] ZENG Hao JIANG Dan-hua CHEN Ming-hui HUANG Xuan LIU Rui-hong GUO Peng WANG Yi-ming FANG Qun(Department of Medical Genetics, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China Reproductive Medicine Center Fetal Medicine Center, Department of Obstetrics and Gynecology Department of Orthopaedics, Huangpu Branch, The First Affiliated Hospital, Sun Yat-sen University Xinhua College, Sun Yat-sen University, Guangzhou 510080, China)

机构地区：[1]中山大学中山医学院遗传学教研室,广东广州510080 [2]中山大学附属第一医院生殖医学中心 [3]中山大学附属第一医院胎儿中心,广东广州510080 [4]中山大学附属第一医院东院下肢骨科,广东广州510080 [5]新华学院,广东广州510520

出　　处：《中山大学学报（医学科学版）》2016年第5期657-665,共9页Journal of Sun Yat-Sen University:Medical Sciences

基　　金：国家自然科学基金(31471193)

摘　　要：【目的】对2例恶性石骨症以及1例ADOⅡ型石骨症患者的致病基因TCIRG1及CLCN7进行致病性突变的研究,以扩展突变谱,为开发针对突变类型的产前诊断性芯片的设计提供数据支持。【方法】收集3名石骨症患者及其父母的外周血,提取DNA,PCR扩增TCIRG1及CLCN7基因的所有外显子及剪切位点序列,对PCR产物进行Sanger测序并进行生物信息学分析,同时对新发现的突变在50名正常对照中进行测序,以排除良性多态性。【结果】在患者1的TCIRG1基因第4外显子发现缺失突变c.242del C(p.Pro81Argfs X85),在第9外显子检测到缺失突变c.965del C(p.Arg323Glyfs X23);在患者2的TCIRG1基因第11外显子发现错义突变c.1213G>A(p.Gly405Arg),第18外显子检测到无义突变c.2181C>A(p.Cys727X);在家系3先证者的CLCN7基因发现无义突变c.1641C>A(p.Trp547X)。其中,TCIRG1基因中的c.965del C(p.Arg323Glyfs X23)和c.2181C>A(p.Cys727X),CLCN7基因中的c.1641C>A(p.Trp547X)均为新突变。【结论】发现TCIRG1基因中2个新突变c.965del C(p.Arg323Glyfs X23)和c.2181C>A(p.Cys727X),2个已报道的突变c.242del C(p.Pro81Argfs X85)及c.1213G>A(p.Gly405Arg),发现CLCN7基因的1个新突变c.1641C>A(p.Trp547X),丰富了TCIRG1及CLCN7基因突变谱,为阐明石骨症的发病机制以及针对本病的诊断性芯片的设计提供了新数据。[Objective] To investigate the causative mutations of TCIRG1 and CLCN7 gene in three sporadic osteopetrosis patients. This is aimed to expand the mutational spectrum of these genes and to provide data for the design of microarrays for prenatal diagnosis for this lethal/disabling disease, which is the best way to prevent patients from being born, as there is currently no cure to the disease. [Methods] Genomic DNA was extracted from peripheral blood of the patients and their parents. All exons and the splice sites of TCIRG1 and CLCN7 gene were amplified by polymerase chain reaction （PCR） followed by Sanger sequencing. 50 healthy unrelated subjects were also sequenced for the novel mutation identified in the genesas controls. [Results] Three novel mutations were identified. In TCIRG1 gene, we identified two novel mutations c.965delC （p.Arg323GlyfsX23） and c.2181C〉A（p.Cys727X） and the two known mutations c.242delC （p.ProglArgfsX85） and c.1213G〉A （p.Gly405Arg）. The two novel mutations truncate 486 and 104 amino acids at the C-terminal of the protein respectively and wipe out part of ATPase V0 complex. These mutations were predicted to result in loss of function of the encoded protein. In CLCN7 gene, the novel mutation c.1641C〉A （p.Trp547X） was identified, which truncates 259 amino acids from the C-terminus and resulting in the loss of two transmembrane domains and two domains in cystathionine [3-synthase. These novel mutations were absent in 50 control subjects. [Conclusions] We detected three novel mutations, c.965delC （p.Arg323GlyfsX23）, c.2181C〉A（p.Cys727X） in TCIRG1 and c.1641C〉A（p.Trp547X） in CLCN7. Our data provide novel information for the mutational spectrum of the genes, which are applicable in the design of microarrays for genetic testing and diagnosis. Our data also provide insight into the pathogenesis of the disease.

关 键 词：石骨症 TCIRG1基因 CLCN7基因 突变 

分 类 号：R394.3[医药卫生—医学遗传学]