Growth and psychomotor development of patients with Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is one of the most common hereditary degenerative neuromuscular diseases and caused by mutations in the dystrophin gene. The objective of the retrospective study was to describe growth and psychomotor development of patients with DMD and to detect a possible genotype–phenotype correlation. Data from 263 patients with DMD (mean age 7.1 years) treated at the Departments of Pediatric Neurology in three German University Hospitals was assessed with respect to body measurements (length, weight, body mass index BMI, head circumference OFC), motor and cognitive development as well as genotype (site of mutation). Anthropometric measures and developmental data were compared to those of a reference population and deviations were analyzed for their frequency in the cohort as well as in relation to the genotypes. Corticosteroid therapy was implemented in 29 from 263 patients. Overall 30% of the patients exhibit a short statue (length < 3rd centile) with onset early in development at 2–5 years of age, and this is even more prevalent when steroid therapy is applied (45% of patients with steroid therapy). The BMI shows a rightwards shift (68% > 50th centile) and the OFC a leftwards shift (65% < 50th centile, 5% microcephaly). Gross motor development is delayed in a third of the patients (mean age at walking 18.3 months, 30% > 18 months, 8% > 24 months). Almost half of the patients show cognitive impairment (26% learning disability, 17% intellectual disability). Although there is no strict genotype–phenotype correlation, particularly mutations in the distal part of the dystrophin gene are frequently associated with short stature and a high rate of microcephaly as well as cognitive impairment.     

Comparison of dystrophin expression following gene editing and gene replacement in an aged preclinical DMD animal model

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Duchenne/becker muscular dystrophy carrier detection using quantitative PCR and fluorescence-based strategies

Dystrophin gene deletions account for up to 68% of all Duchenne (DMD) and Becker (BMD) muscular dystrophy mutations. In affected males, these deletions can be detected easily using multiplex PCR tests which monitor for exon presence. In addition, quantitative dosage screening can discriminate female carriers. We previously analyzed multiplex PCR products by gel electrophoresis and quantitation of fluorescently labeled primers with the Gene Scanner? in order to test carrier status. These multiplex PCR protocols detect DMD gene deletions adequately, but require up to 18 pairs of fluorochrome-labeled primers. We previously described two alternative fluorescent labeling strategies, each with approximately 1,000-fold greater sensitivity than ethidium bromide staining, which can be used to quantify the products of multiplex PCR. The first method uses the DNA intercalating thiazole orange dye TOTO-1 to stain PCR products after 20 cycles. In the second method, fluorescein-12,2′-dUTP is incorporated into products during PCR as a fluorescent tag for subsequent quantitative dosage studies. Both methods label all multiplexed exons including the 506 bp exon 48 fragment that is difficult to detect and quantify by standard ethidium bromide staining. Using this approach, we determined DMD/BMD carrier status in 24 unrelated families using a fluorescent fragment analyzer. Analysis of fluorochrome-labeled PCR products facilitates quantitative multiplex PCR for gene-dosage analysis. © 1993 Wiley-Liss, Inc.     

散发型DMD/BMD家系突变分析及产前诊断研究

目的 分析散发型DMD/BMD家系中患者的致病突变,为部分家系的胎儿进行产前基因诊断,明确该类家庭中女性成员是否致病突变携带者,分析该类家系新发突变的比例.方法 共收集30个散发DMD/BMD家系,应用传统mPCR方法 分析DMD基因缺失热区中的18个外显子;应用MLPA方法,对家系中的30例患者及23个家系中的28位女性成员,进行DMD基因全部79个外显子的定量分析,并为其中19个家系进行20例产前诊断.结果 mPCR检测到19例缺失突变;MLPA检测到21例缺失突变和3例重复突变,并明确缺失突变范围.在检测到突变的家系中,10例母亲为缺失突变携带者,2例为重复突变携带者,9例母亲不是携带者,新发突变比例为37.5%.7例患者的姐妹中5例为携带者(3例缺失,2例莺复),2例不是携带者.经产前诊断,12例男性胎儿中5例为患者,8例女性胎儿中2例为携带者.结论 MLPA方法 可全面检测DMD基因缺失及重复突变、明确女性携带者,为产前诊断提供准确信息.     

Duchenne肌营养不良患者的脊柱融合

目的：观察肌营养不良患者脊柱固定融合术的疗效。方法：对１９８２～１９９５年接受脊柱融合的１２例肌营养不良患者的病历和Ｘ线片进行回顾性研究。随访时间不少于１年。资料包括患者术前肺功能、手术步骤、随访时Ｘ线片Ｃｏｂｂ角和骨盆倾斜程度及患者功能状态。结果：手术时患者年龄为１３５岁,术前肺功能为５６％,脊柱侧凸平均４８°,骨盆倾斜平均１５°,所有患者均接受后路融合双鲁氏棒固定术和髂骨植骨。最后随访时没有发现不融合病例,脊柱侧凸平均３１°,骨盆倾斜平均８°,所有患者均能够坐位而无不适。结论：后路融合双鲁氏棒固定术有助于维持肌营养不良患者的脊柱序列,建议对该类患者在脊柱侧凸发展至３０°前行脊柱融合术。     

假肥大型肌营养不良患者血清相关酶的变化及其意义

目的研究假肥大型肌营养不良(DMD)患者血清中肌酸激酶(CK,EC2.7.3.2),天门冬氨酸氨基转移酶(ASTEC2.6.1.1)和丙氨酸氨基转移酶(ALT,EC2.6.1.2)的变化,为判断DMD患者病情和与其它疾病鉴别诊断提供依据。方法采用全自动生化分析仪测定血清中CK、AST和ALT活性。结果随着年龄的增长,3种酶的活性下降,DMD患者各年龄组与对照组CK、AST和ALT均有显著性差异(P＜0.01),并且DMD各年龄组本身也有显著性差异(P＜0.05)。结论DMD患者病情愈严重,CK、AST和ALT下降得愈多。同时DMD患者CK/AST比值与心肌梗死(AMI)和肝脏疾病都有明显差异。     

症状前期进行性肌营养不良患儿24例病例系列报告

背景：进行性肌营养不良（PMD）中Duchenne型肌营养不良(DMD)和Becker型肌营养不良(BMD)的临床表现、治疗和预后差异明显,目前国内外对症状前期PMD患儿的诊断尚无共识。 目的：探讨婴幼儿时期症状前期PMD患儿的临床特征和实验室检查特点,并探讨血清肌酶水平在DMD和BMD分型诊断中的价值。 设计：病例系列报告。 方法：收集2016年1月至2020年7月江西省儿童医院确诊的症状前期PMD患儿,分析临床特征和实验室检查特点,并以基因检测结果为诊断标准分为DMD组和BMD组,血清肌酶通过ROC曲线分析以约登指数最大值时的取值作为诊断界值,比较不同肌酶的诊断准确性。 主要结局指标：PMD患儿的临床表现、基因结果、血清酶水平（AST、ALT、LTH、CK、CK-MB）。 结果：24例PMD患儿纳入分析,其中DMD组18例,BMD组6例。22例（91.7%）因发现转氨酶升高就诊,2例（8.3%）因亲戚确诊前来就医。PMD患儿CK-MB、CK、LDH、AST和ALT水平均明显升高,DMD组均高于BMD组（除AST外,P均<0.05）。当ALT>224.5 U·L-1、CK>11 069 IU·L-1、CK-Mb>204 IU·L-1、LDH>1 349.5 IU·L-1时为DMD的可能性更高,尤其是LDH>1 349.5 IU·L-1具有高度特异性。 结论：血清肌酶水平增高为 PMD 患儿症状前期的主要表现。LDH＞1 349.5 IU·L-1对诊断DMD具有高度特异性。     

Genetic modifiers of Duchenne and facioscapulohumeral muscular dystrophies

Muscular dystrophy is defined as the progressive wasting of skeletal muscles that is caused by inherited or spontaneous genetic mutations. Next‐generation sequencing has greatly improved the accuracy and speed of diagnosis for different types of muscular dystrophy. Advancements in depth of coverage, convenience, and overall reduced cost have led to the identification of genetic modifiers that are responsible for phenotypic variability in affected patients. These genetic modifiers have been postulated to explain key differences in disease phenotypes, including age of loss of ambulation, steroid responsiveness, and the presence or absence of cardiac defects in patients with the same form of muscular dystrophy. This review highlights recent findings on genetic modifiers of Duchenne and facioscapulohumeral muscular dystrophies based on animal and clinical studies. These genetic modifiers hold great promise to be developed into novel therapeutic targets for the treatment of muscular dystrophies. Muscle Nerve 57 : 6–15, 2018     

The assessment of sniff nasal inspiratory pressure in patients with Duchenne muscular dystrophy in China

Objective

Progressive weakness of respiratory muscles remains one of the leading causes of death among patients with Duchenne muscular dystrophy (DMD). Currently, there are few pulmonary function data among Chinese DMD patients. This study was carried out to evaluate the sniff nasal inspiratory pressure (SNIP) change among a group of Chinese DMD patients, and compare it with the SNIP value of patients with neuromuscular disorders in other countries.