Duchenne/Becker肌营养不良症家系基因分析

目的　对 1 8个DMD BMD基因 1 31例成员进行基因分析。　　方法　采用多重聚合酶链反应(mPCR)和短串联重复序列 (STR)多态单体连锁分析。　　结果　 1 0例男性胎儿中 4例存在基因缺失 ,4例非缺失型男性胎儿单体型与其携带者母亲相同 ,确定为DMD胎儿。 8例女性胎儿中 4例继承了母亲的单体型 ,为致病基因携带者。 46例先证者母亲及其他女性血亲为杂合型。 5′CA ,MP1P和内含子 44,49这 4个位点的杂合率分别为 65 2 % ,47 8% ,80 4%和 93 5%。　　结论　同时选择DMD基因两端和基因内 4个CA或TTGA位点进行联合分析 ,可大大提高诊断的准确率。     

联合应用PCR-SSCP、PCR-限制性酶切和连锁分析法对脊髓性肌萎缩症进行产前基因诊断

目的：建立脊髓性肌萎缩症（SMA）的基因诊断方法。并且应用于SMA的产前基因诊断。方法：应用聚合酶链反应（PCR）－单链构像多态性（SSCP）分析和PCR－限制性酶切分析法对运动神经元存活基因（SMNT）的第7外显子进行缺失检测;应用紧靠SMN基因的微卫星标记进行单体型连锁分析。结果：家系1的患者为两个SMNT基因的同源缺失,胎儿虽然未发现SMNT基因的同源缺失,但是从母亲那儿遗传了一条与患者相同的异常5号染色体,是SMA携带者;家系2的胎儿亦未发现SMNT基因的同源缺失,两家系先证者的母亲各生下了一名正常儿。结论：PCR－SSCP分析,PCR－限制性酶切和单体型连锁分析法是诊断SMA的有效方法,三者联合使用可以相互验证,互为补充,提高产前基因诊断的准确率成功率。     

Duchenne肌营养不良症高风险家系的产前基因诊断

目的 研究Ｄｕｃｈｅｎｎｅ肌营养不良症家系中高风险孕妇的产前基因诊断。方法 应用ＰＣＲ方法扩增６个分布于ＤＭＤ基因全长范围的ＣＡ重复序列多态标记,对４个ＤＭＤ有系进行单体型连锁分析及孕妇的产前基因诊断。结果 这６个ＣＡ多态位点可提供足够的多态信息量,４个家系的所有成员均获得了完整准确的基因单株型,连锁分析诊断出２例ＤＭＤ男胎,１各正常男胎和２名正常女胎,并经出生后检测证实。     

肝豆状核变性的基因诊断

应用ｐＣＲ１３２４探针（Ｄ１３Ｓ３１）检测了中国人中ＴａｑⅠ和ＰｖｕⅡ位点的多态性、多态片段及频率，分别为：ＴａｑⅠ位点，４．２ｋｂ（０．６０）／６．５ｋｂ（０．４０）（ＰＩＣ０．３６）；ＰｖｕⅡ位点，４．６ｋｂ（０．６４）／６．５ｋｂ（０．３６）（ＰＩＣ０．３５）；与白种人相似。由此二位点组成４种单体型，频率分别为０．２６、０．３４、０．１５和０．２５，ＰＩＣ为０．７２。应用此二位点及ＲＢ／ＸｂａⅠ和Ｄ１３Ｓ２６／ＨｐｈⅠ位点对北方地区２０个肝豆状核变性家系进行ＲＦＬＰ单体型连锁分析，确定了相关个体的基因型。     

肝豆状核变性的基因诊断

应用ｐＣＲ１３２４探针（Ｄ１３Ｓ３１）检测了中国人中ＴａｑⅠ和ＰｖｕⅡ位点的多态性、多态片段及频率，分别为：ＴａｑⅠ位点，４．２ｋｂ（０．６０）／６．５ｋｂ（０．４０）（ＰＩＣ０．３６）；ＰｖｕⅡ位点，４．６ｋｂ（０．６４）／６．５ｋｂ（０．３６）（ＰＩＣ０．３５）；与白种人相似。由此二位点组成４种单体型，频率分别为０．２６、０．３４、０．１５和０．２５，ＰＩＣ为０．７２。应用此二位点及ＲＢ／ＸｂａⅠ和Ｄ１３Ｓ２６／ＨｐｈⅠ位点对北方地区２０个肝豆状核变性家系进行ＲＦＬＰ单体型连锁分析，确定了相关个体的基因型。     

Wilson病与微卫星DNA的连锁分析

目的探索国人Ｗｉｌｓｏｎ病（ＷＤ）基因位点（ＷＮＤ）与ＡＦＭ２３８ｖｃ３、Ｄ１３Ｓ３０１、Ｄ１３Ｓ３１６、Ｄ１３Ｓ２９６、及ＡＦＭ０８４ｘｃ５等５个微卫星ＤＮＡ（ＳＴＲ）之连锁关系，对ＷＮＤ进行精确定位。为ＷＤ基因克隆奠定基础。方法对２０个ＷＤ家系１１３名成员及１００名正常对照组成员的ＤＮＡ进行５个ＳＴＲ的聚合酶链反应（ＰＣＲ）扩增片段长度多态性分析；对ＷＮＤ及５个ＳＴＲ进行二点配对及多点连锁分析。结果ＷＮＤ与Ｄ１３Ｓ３０１、Ｄ１３Ｓ３１６、Ｄ１３Ｓ２９６呈紧密连锁，与ＡＦＭ２３８ｖｃ３及ＡＦＭ０８４ｘｃ５呈中度连锁。结论ＷＮＤ与５个ＳＴＲ的遗传连锁图谱为：着丝点—ＡＦＭ２３８ｖｃ３—Ｄ１３Ｓ３０１—ＷＮＤ—Ｄ１３Ｓ３１６—Ｄ１３Ｓ２９６—ＡＦＭ０８４ｘｃ５—端粒     

两步多重聚合酶链反应对假肥大型肌营养不良的基因诊断

应用分子生物学技术，用９组寡核苷酸引物分两步多重聚合酶链反应（ｍＰＣＲ）扩增ｄｙｓｔｒｏｐｈｉｎ基因的９段脱氧核糖核酸（ＤＮＡ）序列。对３６例ＤＭＤ和４例ＢＭＤ进行基因诊断。首先用缺失率较高的５对引物扩增，检出缺失者１７例，再用４对引物扩增，检出缺失者２例。这样，９对引物多重ＰＣＲ总缺失率占受检患者的４７．５％，表明此法可检测出７９．１％左右有基因缺失的患者。实验结果提示，两步多重ＰＣＲ可用于ＤＭＤ／ＢＭＤ的基因诊断。文中从ＤＭＤ／ＢＭＤ的临床表型与基因缺失的关系上进行了比较、探讨。     

两步—多重PCR诊断134例假肥大型进行性肌营养不良症基因缺失

研究临床检测假肥大型进行性肌营养不良症（ＤＭＤ／ＢＭＤ）基因缺失的有效手段。方法运用两步－多重聚合酶链反应（ＰＣＲ）技术诊断ＤＭＤ／ＢＭＤ基因缺失。结果１３４例病人中，检测阳性率为４９．３％（６６／１３４）。结论多重ＰＣＲ诊断ＤＭＤ／ＢＭＤ基因缺失敏感、快速、准确，可在临床推广应用。     

定量PCR对缺失型DMD基因携带者诊断价值的探讨

定量ＰＣＲ对缺失型ＤＭＤ基因携带者诊断价值的探讨李洵桦刘焯霖梁秀龄Ｄｕｃｈｅｎｎｅ型肌营养不良症（ＤＭＤ）是一种Ｘ连锁隐性遗传的神经肌肉疾病，目前，尚缺乏有效的治疗方法，故ＤＭＤ基因携带者的检出仍是防止患病婴儿出生的主要方法之一。本研究根据缺失型ＤＭ...     

迪谢内/贝克肌营养不良症基因缺失的分布

目的分析迪谢内／贝克肌营养不良症（ＤＭＤ／ＢＤＭ）基因缺失类型及其分布规律。方法采用全长ｃＤＮＡ探针和１８对引物多重聚合酶链反应（ｍＰＣＲ）检测１３８例ＤＭＤ／ＢＭＤ。结果用全长ｃＤＮＡ探针，ＤＮＡ印迹法检测出８６例患者基因缺失和４例重复，缺失率为６２．３％。用１８对引物ｍＰＣＲ检测出８２例缺失，占全长ｃＤＮＡ探针检出缺失的９５．４％。结论基因缺失的分布具有一定的规律性。８６例缺失主要集中在两个缺失热区内，其中５９例（６８．６％）分布于外显子４４～５２，相当于ｃＤＮＡ８和７的３′端４个外显子覆盖的区域内。２３例缺失（２６．７％）分布于５′端外显子１～１９，相当于探针１～２ａ和２ｂ～３的检测区域内。仅４例（４．７％）缺失分布于基因的中心区。基因缺失的类型及分布与表型有一定关系。     

Intragenic DNA polymorphism analysis of DMD/BMD dystrophy gene for carrier and prenatal diagnosis in 60 Iranian healthy individuals

Duchenne and Becker muscular dystrophies (DMD/BMD) are allelic, x-linked neuromuscular disease resulting from mutations in dystrophin gene. DMD is the most severe and frequent inherited but still incurable disease in males. About two-third of such patients have large deletions or duplications that can be identified by multiplex polymerase chain reaction (PCR). In one-third of remaining cases, a linkage analysis that involves DNA markers of intragenic dystrophic gene is considered a rapid and simple method for carrier detection and prenatal diagnosis. In the present study, we investigated frequency and heterozygosity of three polymorphic restriction sites and also four highly polymorphic (CA)(n) repeat microsatellites loci within hot spots region of human dystrophin gene in 60 healthy Iranian populations. Our findings indicated that the allele frequencies of pERT87-8/TaqI, pERT87-15/BamHI, and pERT87-15/XmnI were 0.23/0.77, 0.221/0.779, and 0.239/0.761, respectively. Among these three polymorphic sites, pERT78-15/XmnI locus had the highest heterozygosity with frequency of 47.17%. We also found that STR49 had the highest heterozygosity among four polymorphic microsatellites. These findings are useful in linkage analysis of Iranian DMD families in both carrier detection and prenatal diagnosis.     

Prenatal diagnosis of Duchenne/Becker muscular dystrophy by short tandem repeat segregation analysis in Argentine families

Introduction: Duchenne/Becker muscular dystrophies (DMD/BMD) are X‐linked recessive diseases caused by mutations in the dystrophin gene. Methods: We used multiplex polymerase chain reaction (PCR) and short tandem repeat (STR) segregation analysis for DMD/BMD‐carrier detection and prenatal diagnosis. Results: Twenty‐four at‐risk pregnancies were evaluated: 17 were excluded from carrying dystrophin gene mutations with 95–100% certainty. Of the remaining cases, 2 were determined to carry a dystrophin gene mutation with 95–100% certainty. Three cases had a 67% probability of carrying the mutation, and 2 others were not informative. The certainty of the test increased to ∽100% in some cases due to the identification of several genetic events: 4 recombinations; 4 de novo mutations; and 8 deletions encompassing some of the STRs evaluated. Discussion: Overall, 19 of 24 (79%) molecular prenatal diagnoses were informative, indicating that multiplex PCR/STR segregation analysis is a reliable method for carrier detection and prenatal diagnosis when other more sophisticated techniques are unavailable. Muscle Nerve, 2011     

Deletion analysis of the dystrophin gene in Duchenne and Becker muscular dystrophy patients: use in carrier diagnosis

The dystrophin gene was analyzed in 8 Duchenne muscular dystrophy (DMD) and 10 Becker muscular dystrophy (BMD) unrelated families (22 subjects: 18 index cases and 4 sibs) for the presence of deletions by multiplex polymerase chain reaction (mPCR; 27 exons) and Southern hybridization using 8 cDMD probes. Deletions were identified in 5 DMD and 7 BMD patients (6 index cases and 1 sib). The concordance between the clinical phenotype and "reading frame hypothesis" was observed in 11/12 patients (92%). The female relatives of DMD/BMD patients with identifiable deletions were examined by quantitative mPCR. Carriers were identified in 7 families. We also describe a variation in the HindIII pattern with cDNA probe 8 and 11-14. Molecular characterization of the dystrophin gene in this study has been helpful in advising the patients concerning the inheritance of the condition, and carrier diagnosis of female relatives, and should also prove useful for prenatal diagnosis.     

Detection of Duchenne and Becker muscular dystrophy carriers by quantitative multiplex polymerase chain reaction analysis.

We developed a method for the detection of Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) carriers. The method is based on the quantitative analysis of the products of standard multiplex polymerase chain reaction (PCR) from 18 different exons of the dystrophin gene, and is designated "QM-PCR." We detected deletions of one or more exons by standard multiplex PCR in DMD/BMD patients in 14 of 18 families examined (77.7%). The same deletions were readily demonstrated by QM-PCR in nine of 14 mothers (64.3%) and in another six of 22 possible carriers in these families. In five families where deletions were detectable in DMD/BMD patients, the mothers did not exhibit any deletions in their peripheral blood (35.7%). We obtained evidence for germinal mosaicism in at least two of these families and confirmed carrier identification by haplotype analysis using CA repeat polymorphisms at the 5' and 3' ends of the dystrophin gene. Furthermore, analysis of 17 coded DNA samples from normal females and obligatory carriers by QM-PCR showed that this technique could directly identify carriers of deletions in any of 18 different exons of the dystrophin gene. Its application in combination with existing techniques is expected to significantly improve the accuracy of carrier diagnosis in many families, and it may also be applicable to families in which pedigree and polymorphism information is insufficient for carrier diagnosis.     

Carrier detection of Duchenne/Becker muscular dystrophy: computer-assisted direct quantitation of gene amplification products.

An improved method by quantitative dystrophin gene deletion analysis was developed for the detection of Duchenne/Becker muscular dystrophy (DMD/BMD) carriers. Exon 52, which had been found to be deleted in DMD probands, was amplified for female family members, together with exon 60 as a reference, at the exponential phase of polymerase chain reaction. The products were separated by electrophoresis, the band intensities on gel photographs were quantitated, and the target/control ratios were calculated. The values for three heterozygous mothers were approximately half those for normal individuals and two definite non-heterozygous mothers. This procedure is easy, rapid and useful for the carrier diagnosis of DMD/BMD.     

Two mutations in one dystrophin gene

Background and purposeDuchenne/Becker muscular dystrophies (DMD/BMD) lead to progressive irreversible muscle deterioration caused by recessive mutations in the dystrophin encoding gene (Xp21.1). Approximately 60% of mutations are deletions, 10% are duplications and the remaining 30% are point mutations. The aim of the study is to present the rare occurrence of two pathogenic mutations (deletions or duplications) in one allele of the dystrophin gene.Material and methodsDNA of patients from 1364 DMD/BMD families was tested. Two techniques – PCR-multiplex and multiplex ligation-dependent probe amplification – were used to search for mutations in the dystrophin gene.ResultsDeletion was detected in 648 families and duplication was found in 74 families (analysis in progress). In two families, presence of two mutations in one gene was documented – in the first family two deletions were found (exons 45–49 and 60–61), and in the second family two duplications were detected (exons 2–7 and 50–59). One of the deletions disrupted the reading frame, and the other deletion retained the reading frame. Both duplications also retained the reading frame of the gene but in both families the disease took a severe course (DMD). In the family with two duplications prenatal diagnosis was also carried out, and carriership of both mutations was discovered in the female fetus.ConclusionsIn the analyzed group of DMD/BMD families, the frequency of combined occurrence of two mutations in one gene was 2 per 722 (0.3%). The phenomenon of detected non-contiguous deletions and duplications is presented together with 31 similar cases published so far.     

Prenatal diagnosis of Menkes disease by genetic analysis and copper measurement

Carrier detection for 12 women and prenatal diagnosis for six fetuses in Japanese families with a patient with Menkes disease (MNK) were performed by gene analysis and/or measurement of the copper concentration in cultured cells. Six out of eight mothers of MNK patients were carriers while two (25%) were not carriers. Two unrelated patients showed the same mutation (R986X): one patient's mother was a carrier while the other was not. One male and three female fetuses did not have the same mutant allele as the respective MNK proband and have been healthy since birth. One female fetus had the same mutant allele as her affected brother. Gene analysis is very useful and reliable, although such examination is only indicated in families in which a mutation has been identified. In one family in which a mutation in ATP7A was not found, cultured amniocytes from a male fetus had a high copper concentration. Thus after his birth, the biochemical findings confirmed the presence of MNK and early treatment was started. As his early treatment with parenteral copper-histidine prevented the neurological disorders effectively, prenatal diagnosis is very important.     

假肥大型肌营养不良症40例临床特征与基因诊断

目的对假肥大型肌营养不良症（DMD／BMD）患者总结其临床特征并进行基因诊断,以提高对DMD／BMD疾病的认识及诊断水平。方法对40例DMD／BMD患者临床特征进行总结包括临床表现、血清肌酶、肌电图及肌肉活检等,并应用18对引物多重PCR的方法对其进行Dystrophin基因缺失诊断。结果DMD／BMD为儿童期隐匿起病、缓慢进行性加重,以肌无力和肌萎缩为特点,主要选择性侵犯四肢近端肌、盆带肌、腰带肌等,可有肌肉假性肥大,有些患者可有智能减退和心肌损害;血清肌酶水平异常增高,肌电图示肌源性损害,肌肉活检呈肌病特征。基因诊断27例存在外显子片段缺失,13例未检测到缺失。结论识别DMD／BMD的临床特征有助于提高对其的诊断水平,多重PCR作为一种简便快速的诊断方法可对DMD／BMD患者进行基因诊断。     

定量PCR法对缺失型DMD家系携带者诊断价值的研究

目的探讨紫外凝胶分析系统定量PCR方法对缺失型杜(氏)/贝(氏)进行性肌营养不良(DMD/BMD)携带者的诊断价值。方法采用紫外凝胶分析系统定量检测16个缺失型DMD/BMD家系中的19名女性亲属和15名健康对照的二重PCR产物,并计算计量系数DQ值。结果定量PCR方法将9名女性确定为携带者。结论定量PCR方法是一种准确、快速、简便的DMD携带者诊断方法。