成人型脊髓性肌萎缩症的基因研究

目的：研究我国成人型脊髓性肌萎缩症（SMA）患者的运动神经元生存基因（SMN）及神经细胞凋亡抑制蛋白（NAIP）基因外显子的缺失情况。以探讨此二种基因与成人型SMA之间的关系。方法：应用PCR法检测30例成人型SMA患者，30例表型正常的SMA直系亲属及30例正常对照的SMN基因第7，8号外显子和NAIP基因第5，6号外显子缺失情况。结果：成人型(Ⅳ型）SMA未检测到SMN基因第7，8号外显子及NAIP基因外显子5和（或）6的缺失。结论：成人型SMA未检测到SMN基因缺失，其发病可能与SMN基因缺失无关；NAIP基因在SMA发病中的作用尚不清楚，有待进一步研究。     

运用DHPLC技术分析非纯合缺失型脊髓性肌萎缩症患儿的SMN基因拷贝数

目的 建立一种准确、快捷的方法,定量检测运动神经元存活基因(SMN)的拷贝数,以便分析非纯合缺失型脊髓性肌萎缩症(SMA)患儿中SMNl基因的杂合性缺失.方法 应用等位基因特异PCR(AS-PCR)分别进行SMN1与SMN2基因的特异扩增,用另外2个无关基因作内对照,进行变性高效液相色谱法(DHPLC)分析,确定基因拷贝数.结果 (1)改进的双重AS-PCR与DHPLC相结合的技术,能够有效分离SMN1和SMN2基因,通过与对照基因的对比,可准确地判断SMN基因的拷贝数,SMN1和SMN2基因1～4拷贝之间不存在重叠.(2)38例非纯合缺失SMA患儿中,20例的SMN1基因为1个拷贝(52.6%),判断为SMN1基因的杂合性缺失,其中15例(75.0%,15/20)的SMN2基因为2个拷贝,5例(25.0%,5/20)SMN2基因为3个拷贝.(3)30名SMN1基因纯合缺失型突变患者的双亲中,有24名(80.0%)的SMNl基因为1个拷贝.结论 本研究所建立的方法能够准确、快捷地检测SMN基因的拷贝数.     

脊髓性肌萎缩运动神经元存活基因和神经元凋亡抑制蛋白基因缺失的研究

目的 :研究国人脊髓性肌萎缩 (SMA )基因缺失特点。方法 :应用 PCR扩增及限制性内切酶技术对 15例儿童型 SMA ( 型 7例 , 型 4例 , 型 4例 )和 2例成人型 SMA进行运动神经元存活基因 (SMN)第 7外显子和神经元凋亡抑制蛋白基因 (NAIP)第 5外显子缺失分析 ,并对 1例有阳性家族史的家系进行了羊水胎儿产前诊断。结果 :14例儿童型 SMA携有 SMN基因第 7外显子缺失 ,占 93% ;2例 型 SMA携有 NAIP基因第 5外显子缺失 ,占 2 8.6 %。 2例成人型 SMA未显示 SMN或 NAIP基因缺失。结论 :儿童型 SMA的 SMN基因缺失频率高 ,可应用于临床 ,提高 SMA诊断率 ,适于产前诊断及鉴别诊断。 NAIP基因缺失可能与 SMA的严重程度有关。成人型SMA与儿童型 SMA为非等位基因突变。     

茂名地区育龄妇女脊髓性肌萎缩症SMN1突变携带者筛查与分析

目的 对茂名地区育龄妇女进行脊髓性肌萎缩症(SMA)运动神经元存活基因1(SMN1)突变携带者筛查,掌握SMA流行病学数据,为SMA家系进行遗传咨询、基因筛查和产前诊断提供依据。方法 收集2020年5月-2021年8月在茂名市妇幼保健院进行孕检的1 898名妇女临床资料和肘静脉外周血样本。采用MGB探针实时多重荧光定量PCR法,分别对SMN1第7外显子和第8外显子的拷贝数进行相对定量检测,并分析目的基因的缺失情况及携带频率,为男女双方均为阳性携带者的夫妇进行产前诊断。结果 在1 898名育龄妇女中,共检测出脊髓性肌萎缩症SMN1突变携带者49例,携带率为2.58%;其中SMN1-7杂合缺失/SMN1-8杂合缺失最多33例(1.74%),其次为SMN1-7未见缺失/SMN1-8杂合缺失12例(0.63%)和SMN1-7杂合缺失/SMN1-8未见缺失4例(0.21%)。2对双方均为阳性携带者夫妻的3例胎儿羊水标本中2例为SMN1-7杂合缺失/SMN1-8杂合缺失和SMN1-7杂合缺失/SMN1-8未见缺失,建议继续妊娠;1例为SMN1-7纯合缺失/SMN1-8纯合缺失,建议对胎儿进行终止妊...     

儿童脊肌萎缩症的临床分析与基因诊断

目的对疑似脊髓性肌萎缩症(SMA)患儿进行临床分析和基因诊断,探讨SMA患儿和健康儿童之间运动神经元存活基因2(SMN2)拷贝数分布差异及SMN2拷贝数与SMA临床分型的关系,为临床诊断和早期干预提供依据。方法回顾性分析2016年1月～2019年12月就诊的16例疑似SMA患儿的临床资料,分析临床特点,应用多重链接依赖探针扩增技术(MLPA)对其SMN基因进行检测,并对检出的杂合缺失患儿加做家系Sanger测序,同时选取16例健康儿童作对照。结果 15例确诊为SMA,其中MLPA检出13例患儿SMN1基因外显子7、8纯合缺失;MLPA+Sanger测序检出2例(2/15)患儿SMN1复合杂合突变;1例未检出SMN基因缺失。SMA患儿和健康儿童的SMN2基因拷贝数分布,差异有统计学意义(P<0.05),前者以2～3个为主,后者以1～2个为主;SMN2拷贝数与临床分型之间呈线性正相关(P<0.05),SMN2拷贝数越多,临床表现越不明显。结论对疑诊SMA的患儿,根据其临床特点,结合基因检测结果可明确诊断;对怀疑复合杂合突变患者行Sanger测序有助于明确诊断;SMN2基因可通过...     

DHPLC技术在儿童型脊髓性肌萎缩症的基因诊断及携带者基因筛查中的应用

目的评价变性高效液相色谱（denaturing high performance liquid chromatography,DHPLC）技术在儿童型脊髓性肌萎缩症（spinal muscul aratrophy,SMA）基因诊断及携带者基因筛查中的应用价值。方法对35例临床疑诊为儿童型SMA的患者采用临床标准进行诊断。同时,应用DHPLC技术联合双重PCR对所有入选患者、临床标准确诊为SMA患者的双亲以及一份标准对照进行SMN1拷贝数检测,做出基因诊断及判断携带者。结果（1）35例入选患者,临床标准诊断确诊SMA15例,非SMA20例。（2）DHPLC技术检测35例入选患者：15例临床诊断SMA患者中,12例SMN1拷贝数为0,为纯合缺失型SMA患者;2例SMN1拷贝数为1,为杂合缺失型SMA患者;1例SMN1拷贝数为2,为非SMA。20例临床诊断非SMA者,SMN1拷贝数为2,为非SMA。（3）与临床标准诊断相比,DHPLC技术诊断SMA灵敏度为93.3%,特异度为100%。15例临床确诊为SMA患者的28名双亲中,1例SMN1拷贝数为0,6例SMN1拷贝数为2,21例SMN1基因拷贝数为1（为携带者）,SMA患者双亲的携带率为75%。结论应用DHPLC技术可以检测出SMN1基因拷贝数,进行SMA基因诊断灵敏度和特异度高,适合临床应用;应用该技术可以进行携带者筛查,为遗传分析和产前诊断提供理论依据。     

MLPA方法在脊髓性肌肉萎缩症分子诊断中的应用

目的 探讨多重连接依赖性探针扩增(MLPA)技术在脊髓性肌肉萎缩症(SMA)分子诊断中的应用.方法 从13例SMA患者、31名患者父母的外周血标本和10份胎儿羊水标本,以及50名正常人外周血标本中提取基因组DNA,应用MLPA技术进行分析,同时也行常规聚合酶链反应-限制性片段长度多态性(PCR-RFLP)和位点特异性PCR分析.结果 MLPA分析结果与常规PCR-RFLP和位点特异性PCR结果相符:13例患者的运动神经元存活基因(SMN)1基因均呈纯合缺失,SMN2基因拷贝数的增加与SMA表型的严重程度(从I型到Ⅲ型)存在显著性差异(P<0.05);31名患者父母SMN1基因1拷贝的人数为29(占93.5%),2拷贝的为2(占6.5%);50名正常健康成人SMN1基因1拷贝的人数为1(占2.0%),2拷贝的为48(占96.O%);SMA患者父母组和健康正常成人组之间的SMN1基因拷贝数存在显著件差异(P<0.01);10例胎儿中2例存在SMN1的纯合缺失.结论 MLPA是一种准确可靠的SMA分子诊断新方法.     

成年起病脊肌萎缩症SMN基因外显子7缺失的初探

目的 探讨成年起病的脊肌萎缩症（SMA）患者的运动神经元存活基因SMN的缺失情况。方法 用聚合酶链反应－酶切技术对15例SMA病人及33例正常对照的外显子7进行检测，明显有无缺失。结果 3例SMA的SMN的基因外显子7纯合缺失，其余12例和对照组均阴性。结论 SMN基因外显子7缺失可作为成年起病SMA的辅助诊断，以提示SMA遗传的异质性。     

MLPA联合二代测序、longPCR产物巢式PCR诊断脊髓性肌萎缩一例

在常染色体隐性遗传疾病中,脊髓性肌萎缩(spinal muscular atrophy,SMA)是婴儿和儿童早期死亡的最常见遗传原因[1-2].其致病基因为运动神经元生存基因1 (survival motor neuron 1,SMN1),临床以SMN1基因外显子纯合缺失为主,SMN1基因外显子杂合缺失复合SMN1基因...     

南充地区脊髓性肌萎缩症携带者筛查及高风险胎儿产前诊断分析

目的:分析南充地区脊髓性肌萎缩症(SMA)携带者筛查及高风险胎儿产前诊断。方法:选取4 325例定期产检且因不良妊娠史就医的育龄期女性及183名配偶为研究对象。采用荧光定量聚合酶链式反应(QF-PCR)法检测运动神经元存活基因1(SMN1)7号外显子(E7)的拷贝数。E7拷贝数1为携带者，对夫妻双方均是SMA携带者应用多重连接探针扩增技术(MLPA)验证胎儿SMN1基因拷贝数变异。结果:共检测到SMA携带者70例，携带率为1/64.4,其中E7和8号外显子(E8)双位点杂合缺失的64例(1/70.4),E7位点杂合缺失6例(1/751.3)。对夫妻双方均为杂合性缺失胎儿基因检测发现，胎儿SMN1基因为0个拷贝数，运动元存活基因2(SMN2)为3个拷贝数，最终通过遗传咨询预防了SMA患儿的出生。结论:南充地区SMA的携带率为1/64.4,QF-PCR检测结合MLPA家系验证，并对高风险胎儿进行产前诊断，对减少SMA患儿的出生具有重要诊断价值，对本地区出生缺陷防控有重要的意义。     

Compound heterozygous mutation in two unrelated cases of Chinese spinal muscular atrophy patients

Background Infantile proximal spinal muscular atrophy (SMA) is a common autosomal recessive neuromuscular disorder. Approximately 90%–95% cases of SMA result from homozygous deletion of survival motor neuron gene 1 (SMN1) and 5% cases are caused by compound heterozygous mutation (a SMN1 deletion on one allele and a subtle mutation on the other allele).

Methods In this research, two unrelated patients were clinically diagnosed according to the criteria of proximal SMA. Genetic diagnosis was performed to detect the homozygous deletion of exon 7 of SMN1 by PCR-restriction fragment length polymorphism (RFLP) and genomic sequencing. Multiplex ligation-dependent probe amplification (MLPA) analysis was carried out to measure copy numbers of SMN1, SMN2 and neuronal apoptosis inhibitor protein (NAIP) in the patients. Further sequencing of SMN1 allele-specific PCR (AS-PCR) and SMN1 clones were also performed to analyze the point mutation of SMN1 gene. Additionally, the pedigree analysis of these two families was carried out to identify the transmission of the mutation.

Results The inconsistent results using PCR-RFLP and genomic sequencing showed homozygous deletion of exon 7 of SMN1 and heterozygous deletion accompanied with a suspicious mutation in SMN1 gene, respectively. MLPA analysis of these two cases exhibited one SMN1 copy deletion. One identical c.863G>T (p.Arg288Met) mutation was found in two cases by sequencing the SMN1 clones, which confirmed that both cases were SMA compound heterozygotes. One case showed partial conversion to form hybrid SMN (SMN2 I7/SMN1 E8) identified by clones sequencing and another case carrying 3 SMN2 implied complete conversion from SMN1 to SMN2.

Conclusion p.Arg288Met is more a disease-causing mutation than a polymorphism variation, and children with this mutation may have more severe phenotypes.

     

进行性脊髓性肌萎缩症患者神经元存活基国及神经元凋亡抑制蛋白基因的缺失

目的：研究中国人群中进行性脊髓性肌萎缩症（ｓｐｉｎａｌ ｍｕｓｃｕｌａｒ ａｔｒｏｐｈｙ,ＳＭＡ）患者中神经元存活基因（ｓｕｒｖｉｖａｌ ｍｏｔｏｒ ｎｅｕｒｏｎ,ＳＭＮ）外显子７及神经元调亡抑制蛋白基因（ｎｅｕｒｏｎａｌ ａｐｏｐｔｏｓｉｓ ｉｎｈｉｎｂｉｔｏｒｙ ｐｒｏｔｅｉｎ ｇｅｎｅ,ＮＡＩＰ）外显子５缺失情况,进一步探讨这２个ＳＭＮ基因外显子７区域和５５例患儿ＮＡＩＰ基因外显子５的缺失进行检测。结果：ＳＭＮ基因外显子７区域纯合缺失率分别为：ＳＭＡＩ型９２％（２３／２５）;Ⅱ型９０％（２７／３０）。患儿双亲中有２例母亲的１例父亲也有纯合缺失。在５５例ＳＭＡ患儿中未检测到有ＮＡＩＰ基因外显子５的纯合缺失,仅发现２例杂合性缺失。结论：中国人ＳＭＡ患者中ＳＭN     

Analysis of the survival motor neuron and neuronal apoptosis inhibitory protein genes in Malay patients with Spinal Muscular Atrophy

In Malaysia, Spinal Muscular Atrophy (SMA) is diagnosed based on clinical observation with or without muscle biopsy. Molecular analyses of the SMA-related genes have not been available so far. In this preliminary study, we searched for homozygous deletion of Survival Motor Neuron (SMN1) and Neuronal Apoptosis Inhibitory Protein (NAIP) genes in Malay patients with SMA and found homozygous deletion of SMN1 exon 7 and 8 in all the patients while homozygous deletion of NAIP exon 5 was detected in only our type 1 patients but not in the type 3 patient. To the best of our knowledge, these are the first SMA cases diagnosed at the molecular level in Malaysia.     

SMN基因诊断小儿脊髓性肌萎缩症

目的了解儿童期发作的进行性脊髓性肌萎缩(SMA)患者的运动神经元存活基因(SMN)的缺失,探讨聚合酶链反应-限制性片段长度多态性(PCR-RFLP)方法用于SMA疾病的诊断价值。方法应用PCR-RFLP方法对3例SMA可疑患儿及其父母5例的SMN1基因外显子7和8进行了检测,并对其进行基因测序。结果3例SMA可疑患儿中3例均有SMN1基因缺失,为外显子7和8联合缺失。其父母均无SMN1基因缺失。基因测序支持诊断。结论用PCR-RFLP法对高度可疑儿童型SMA的病例进行诊断,具有较高敏感性和特异性,简便易行。     

应用聚合酶链式反应-酶切法进行脊髓性肌萎缩的基因诊断及产前诊断

目的：建立一种高效,快速的脊髓性肌萎缩（SMA）的基因诊断与产前诊断的方法。方法：基于运动神经元生存基因（SMN）基因的两个同源拷贝碱基上的差异,采用聚合酶链反应（PCR）－酶切的方法,选择特异的酶切位点对11例SMA患儿进行SMN基因检测。同时采用SMN基因内部及旁侧的C161,C171,C212,C272等4对（CA)n对4个家系进行连锁分析。结果：11例SMA患儿中10例患儿缺失SMNt7,8号外显子,1例患儿仅缺失7号外显子。4个SMA家系中有3个胎儿未发现与先证者完全相同的SMN基因片段,1个胎儿检测到与先证者完全相同的SMN基因片段。结论：该方法快速,简便,适合临床推广。     

SMN基因缺失多重连接探针扩增法检测和识别脊柱肌肉萎缩症的纯合型或杂合型SMN基因缺失

Objective: Spinal muscular atrophy(SMA), an autosomal recessive neuromuscular degen-eration of the anterior horn ceils of the spinal cord and brain stem, results in one of the most common dis-eases with muscle fatigue and atrophy. Most SMA cases including all the types are due to the homozygous deletion of at least exon 7 within the survival motor neuron 1 (SMN-1) gene. Although a ““golden stand-ard““ assay ( PCR with mismatch primer followed by enzyme digestion) is very reliable for the identifica-tion of homozygous SMN-1 deletion, the carrier detection of heterozygous SMN-1 deletion remains a chal-lenge. Methods: Some PCR-based gene dosage assays or multiplex PCR allow for the determination of the copy number of SMN-1 gene to identify heterozygous deletion, but these procedures are often time consuming and available on a limited clinical basis. Recently developed MLPA (multiplex ligation-de-to establish the copy number of the SMN gene. We performed a validation for simultaneous detection of homozygous SMN-1 deletions of SMA patients and heterozygous SMN-1 deletions of SMA carriers in a sim-ple assay using a MLPA-SMA assay specific reagent. Results: Six out of 20 patients with SMA were found to have homozygous SMN-1 deletion, confirmed by the PCR/digestion assay. All 4 parents of the children with SMA had heterozygous SMN-1 deletion, confirmed by an independent relative quantitative analysis. Conclusion: MLPA provides a simple, rapid and accurate method of simultaneously detecting homozygous deletions and heterozygous deletions in a sinzle assay for both SMN-1 and SMN-2 zenes.     

Long-term stabilization of respiratory conditions in patients with spinal muscular atrophy type 2 by continuous positive airway pressure: a report of two cases

Spinal muscular atrophy (SMA) type 2 is a motor neuron disease that leads to severe congenital muscle atrophy. The majority of adult patients are at risk of death due to respiratory failure. Here, we report on two patients with SMA type 2 who repeatedly developed bronchitis and pneumonia. The patient in Case 1 was a 48-year-old female lacking exon 7 of the survival motor neuron gene (SMN) 1. The patient in Case 2 was a 37-year-old female lacking exons 7 and 8 in SMN 1 and exon 5 in the neuronal apoptosis inhibitory protein (NAIP) gene. We applied continuous positive airway pressure (CPAP) in both cases because their data on polysomnography showed obstructive sleep apnea (OSA). CPAP treated their respiratory symptoms as well as those due to OSA. Moreover, CPAP stabilized the respiratory condition of Case 1 for seven years and seven months and that of Case 2 for five years and four months. These findings suggest that CPAP alone can achieve long-term improvement in the respiratory condition in patients with SMA type2.