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。     

Full-length dystrophin restoration via targeted exon integration by AAV-CRISPR in a humanized mouse model of Duchenne muscular dystrophy

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Lessons from an Experiential Approach to Patient Community Engagement in Rare Disease

Meaningful engagement between biopharmaceutical companies and patient communities has increasingly become an important part of the therapeutic-development process, as such engagement improves the understanding of the multifaceted challenges and unmet needs that communities experience and provides an opportunity to inform the approach to the development of new therapies and services. Presented here are learnings from a community-advisor program designed to engage families of patients with Duchenne muscular dystrophy (DMD) in a manner that enabled caregivers to make valuable contributions to the therapeutic-development process and to the DMD community. Parents of children with DMD, representing the broader DMD community, were identified in partnership with patient-advocacy organizations and invited to participate in a community-advisor meeting with members of Wave Life Sciences. The community-advisor meeting was designed to provide participants with an opportunity to share their personal experiences with DMD, to help to inform the therapeutic-development process, and to identify potential solutions for addressing unmet needs. Three community-advisor meetings were held with a total of 30 parents, representing 36 children with DMD. Key themes that emerged from the advisors' discussion included the importance of the community's emotional and mental support, the inconsistencies in DMD care, the increased challenges and disparities faced by underserved communities, and the need for more comprehensive, holistic approaches to the treatment and management of DMD. The advisors viewed the meetings as an opportunity to share their voices with a biopharmaceutical company, coupled with the advantage of meeting other families living with similar challenges. Most of the advisors stated that this was their first advisor meeting. This community-focused approach empowered participants to voice their needs and perspectives, to brainstorm potential solutions for addressing those needs, and to initiate and foster connections in ways that had a considerable impact on one another and on therapeutic-development programs at Wave Life Sciences.     

Plasma microRNAs as biomarkers for myotonic dystrophy type 1

Myotonic dystrophy type 1 (DM1) lacks non-invasive and easy to measure biomarkers, still largely relying on semi-quantitative tests for diagnostic and prognostic purposes. Muscle biopsies provide valuable data, but their use is limited by their invasiveness. microRNA (miRNAs) are small non-coding RNAs regulating gene expression that are also present in biological fluids and may serve as diseases biomarkers. Thus, we tested plasma miRNAs in the blood of 36 DM1 patients and 36 controls. First, a wide miRNA panel was profiled in a patient subset, followed by validation using all recruited subjects. We identified a signature of nine deregulated miRNAs in DM1 patients: eight miRNAs were increased (miR-133a, miR-193b, miR-191, miR-140-3p, miR-454, miR-574, miR-885-5p, miR-886-3p) and one (miR-27b) was decreased. Next, the levels of these miRNAs were used to calculate a “DM1-miRNAs score”. We found that both miR-133a levels and DM1-miRNAs score discriminated DM1 from controls significantly and Receiver–Operator Characteristic curves displayed an area under the curve of 0.94 and 0.97, respectively. Interestingly, both miR-133a levels and DM1-miRNAs score displayed an inverse correlation with skeletal muscle strength and displayed higher values in more compromised patients.In conclusion, we identified a characteristic plasma miRNA signature of DM1. Although preliminary, this study indicates miRNAs as potential DM1 humoral biomarkers.     

Histological changes in masticatory muscles of mdx mice

Objective

Duchenne muscular dystrophy (DMD) patients have distorted dentofacial morphology that could be a result of changed force balance of masticatory muscles due to unequal dystrophic changes in various masticatory muscles. Skeletal muscles of DMD patients and those of murine model of DMD - mdx mice - are both characterized by Ca²⁺ induced muscle damage, muscle weakness and characteristic histological changes. Therefore, to determine the pathological changes in this animal model of DMD, we examined the masticatory muscles of the mdx mice for histological abnormalities including nuclei localization, fibre diameters, and collagen expression.

Design

Muscle sections from masseter (MAS), temporal (TEM), tongue (TON) and soleus (SOL) of mdx and control normal mice were stained with hemalaun/eosin or with Sirius Red and morphometrically analysed. Levels of collagen staining in normal and mdx muscles were measured using image analysis and the mean optical density (mod) was determined.

Results

Dystrophin deficient masticatory muscles contained 11-75% fibres with centralised nuclei. In mdx mice an increased mean fibre diameter was observed as compared to the age-matched control muscles (control vs. mdx; MAS: 33.44 ± 0.49 μm vs. 37.76 ± 0.68 μm, p < 0.005; TEM: 32.93 ± 0.4 μm vs. 42.93 ± 0.68 μm, p < 0.005; SOL: 33.15 ± 0.29 μm vs. 40.62 ± 0.55 μm, p < 0.005; TON: 13.44 ± 0.68 μm vs. 15.63 ± 0.18 μm, p < 0.005). Increased expression of collagen was found in MAS (mod control vs. mdx: 1.34 vs. 3.99, p < 0.005), TEM (mod control vs. mdx: 3.11 vs. 4.73, p < 0.01) and SOL (mod control vs. mdx: 2.36 vs. 3.49, p < 0.01).

Conclusion

Our findings revealed that mdx masticatory muscles are unequally affected by the disease process. The masticatory muscles of the mdx mice could present a useful model for further investigating the influence of dystrophin deficiency on muscles function.     

Oral health in children and adolescents with myotonic dystrophy

Myotonic dystrophy or dystrophia myotonica (DM) is a hereditary neuromuscular multisystem disease with a varying clinical expressivity and severity. The objective of this study was to assess the oral health in children with myotonic dystrophy and to compare it with a control group. Fifty-six DM patients, aged 2.7-18.0 yr, were compared with age- and gender-matched control patients with respect to caries, plaque, and gingivitis. Oral function and signs of temporomandibular dysfunction (TMD) were assessed, and the ability to co-operate in dental treatment was estimated. Questionnaires concerning eating habits, dental care, traumatic injuries to teeth, and orofacial function were also used. The DM patients had significantly more caries, plaque, and gingivitis than did control patients. They had more TMD problems and lower co-operation ability than the healthy control persons. General sedation was frequently needed to carry through dental treatment. DM patients are at risk of caries, gingivitis and TMD problems, and need intensified prophylactic care. Behavior management problems are common.     

Slc4a11基因缺失在CHED发病中的作用

目的　探讨Slc4a11缺失在先天性遗传性角膜内皮营养不良（congenital hereditary endothelial dystrophy, CHED）发病中的作用及其与自噬信号通路的潜在调控关系。方法　利用CRISPR/Cas9技术构建Slc4a11基因敲除小鼠模型。以野生型小鼠（wild type, WT）和Slc4a11基因敲除小鼠（knockout, KO）为实验对象,通过Western印迹法、RT-qPCR、茜素红染色、H-E染色、透射电镜评估KO小鼠角膜表型特征的变化。通过Western印迹法和RT-qPCR检测自噬标志物LC3、beclin1、p62在角膜内皮的表达量。透射电镜观察两组小鼠角膜内皮细胞自噬情况。结果　Slc4a11基因敲除小鼠角膜显示与CHED相似的表型特征,包括角膜厚度增加;角膜内皮细胞体积增大,密度减小;后弹力层增厚;角膜内皮空泡形成。KO小鼠与WT小鼠相比,LC3、beclin1的mRNA和蛋白的相对表达量上升,差异有统计学意义（P<005）,而p62的mRNA和蛋白的相对表达量下降,差异有统计学意义（P<005）。KO小鼠角膜内皮细胞内自噬体明显多于WT小鼠。结论　利用CRISPR/Cas9技术构建的Slc4a11基因敲除小鼠角膜显示CHED特征的表型。同时Slc4a11缺失通过增强自噬信号通路参与CHED的发病机制。     

结晶样视网膜色素变性临床与基础研究的机遇与挑战

结晶样视网膜色素变性（Bietti crystalline dystrophy,BCD）是视网膜色素变性中的一种特殊类型,其在东亚人群特别是中国人和日本人中较为常见。BCD的遗传方式为常染色体隐性遗传,唯一的致病基因为CYP4V2。对BCD患者自然史和CYP4V2突变导致BCD机制研究,将对确定BCD患者基因治疗的时间窗、临床研究中治疗效果评定以及探索治疗BCD其他方法均至关重要。（眼科,2020,29： 84-86）     

施奈德结晶状角膜营养不良的分子基础与临床研究进展

施奈德结晶状角膜营养不良(SCCD)是一种稀有的常染色体显性遗传病,其发病部位在眼角膜,伴有结晶状沉淀,双眼发病,家族遗传性,男女患病几率均等。临床研究揭示角膜结晶状混浊化成因是胆固醇、磷脂等脂质在角膜上皮下和基质中异常积累。SCCD的发生与UBIAD1基因突变后脂质代谢异常有关,但是致病的分子机制未知。本文综述了SCCD的发现发展历史、发病分子基础与临床研究,为SCCD的诊疗以及致病分子机制的阐明提供参考。     

D uchenne 型肌营养不良家系的临床及分子遗传学研究

目的：探讨Duchenne型肌营养不良（DMD）家系的临床及分子遗传学特征。方法收集并分析我院收治的2个DMD家系临床资料和基因检测结果,并结合既往相关文献,回顾该病在临床表现、分子遗传学等方面的特点。结果DMD儿童期隐匿起病,进行性加重,以肌无力、肌萎缩为特点,可伴肌肉假性肥大,血清肌酶水平异常增高,肌电图呈肌源性损害,肌肉活检呈肌病特征。本文报道的2个家系经基因检测家系1先证者为DMD基因的第3～21号外显子缺失,家系2先证者则为第8、9外显子重复突变,2个家系中的先证者基因均为纯合突变,且其母亲均为致病基因的携带者,符合X染色体隐性遗传的规律。结论早期识别DMD的临床特征有助于提高该病的诊断水平,基因检测是一种确诊DMD快速、有效的方法。