一个中国肢带型肌营养不良2A型家系的临床和分子遗传学研究  

Clinical and molecular genetic study of limb-girdle muscular dystrophy type 2A in a Chinese family

作　　者：刘爱杰[1] 杨海坡[1] 陈琳[2] 熊晖[1] 

机构地区：[1]北京大学第一医院儿科,100034 [2]中国医学科学院中国协和医科大学北京协和医院神经内科

出　　处：《中华实用儿科临床杂志》2014年第24期1854-1857,共4页Chinese Journal of Applied Clinical Pediatrics

基　　金：国家自然科学基金（81271400）;国家重点基础研究发展计划（2012CB944602）

摘　　要：目的 分析一个肢带型肌营养不良（LGMD）家系的临床特点、肌肉病理特点和致病基因突变,总结表型/基因型关系.方法 收集并分析先证者（女）及其患病胞弟的临床和病理资料,提取2人与父母的外周血DNA.筛选61个与肌肉病相关的致病基因,设计肌病相关基因下一代测序靶向捕获试剂盒Sureselect,采用外显子靶向捕获结合下一代测序技术对先证者进行LGMD相关基因突变检测,发现CAPN3基因变异并经San-ger测序证实后对其弟及父母相同位点进行测序确定变异来源,查单核苷酸多态性数据库（dbSNP138）和基因突变数据库（http：//www.dmd.nl/）,确定致病突变.结果 本研究先证者为儿童期隐匿起病盆带肌为主的肌无力,逐渐表现为蹲下站起、上楼困难,无翼状肩和肥肠肌肥大,伴有跟腱挛缩和血清肌酸激酶（CK）升高（1 908～9 241 IU/L）,弟弟表现为“高CK血症”.利用外显子靶向捕获结合下一代测序技术对此临床诊断为LGMD患者进行基因筛查,发现姐弟均携带CAPN3基因的一个位点c.717delT及另一个位点c.2243G＞A的突变,并经一代测序验证,二者均为已报道致病突变.结论 LGMD临床和遗传异质性明显,外显子靶向捕获结合下一代测序技术能快速发现LGMD的致病基因突变,以利进一步准确进行基因型/表型分析。Objective To analyze the clinical,muscle pathological features and molecular mutations in the 2 Chinese Han siblings with limb-girdle muscular dystrophy（LGMD） and conclude the phenotype/genotype correlations.Methods Clinical and muscle pathological data were collected.Genomic DNA of the two siblings and their parents were extracted using standard procedures from the peripheral leukocytes.A custom of targeted gene panel including 61 neuromuscular genes were designed by using the Agilent Sureselect Target Enrichment Kit.Targeted next generation sequencing（NGS） was performed in the proband,and CAPN3 gene mutation was verified with Sanger sequencing in the two siblings and their parents.The dbSNP138 and http：//www.dmd.nl were searched to determine the disease-causing mutations.Results The proband slowly showed muscle weakness profoundly with pelvic muscles,developed difficulty in squatting and standing and climbing stairs.She had a tight Achilles tendon,high CK level （1 908-9 241 IU/L）,without winging scapula and hypertrophy calf.The affected brother was only diagnosed ＂hyper CKemia＂.By using the targeted NGS,the two siblings possessed the same two compound heterozygous mutations（c.717delT and c.2243G ＞ A） in CAPN3 gene.The two mutations both were verified by Sanger sequencing and had been reported before.Conclusions LGMD is clinically and genetically heterogeneous,and targeted NGS is powerful in defining the causal mutation of LGMD and helpful in investigating the exact genotype/phenotype analysis.

关 键 词：肢带型肌营养不良2A CAPN3基因 下一代测序 突变 

分 类 号：R746.2[医药卫生—神经病学与精神病学]