Infantile Spinal Muscular Atrophy at the Albert Royer National Children’s Hospital Center in Dakar

Introduction: Infantile spinal muscular atrophy (ISA) is an autosomal recessive disease caused by primary degeneration of cells in the anterior horn of the spinal cord, leading to muscle weakness and hypotonia. Its incidence is estimated at 1 in 6000 births worldwide. In Africa, particularly in Senegal, there are few studies interested on this pathology. We therefore deemed this study necessary, which set itself the objective of describing the diagnostic, therapeutic and progressive aspects of infantile spinal muscular atrophy at the Albert Royer National Children’s Hospital Center in Dakar (CHNEAR). Methodology: We conducted a retrospective descriptive study over a period of two (2) years from December 2020 to December 2022. Included were all hospitalized patients in whom the diagnosis of spinal muscular atrophy was made with or without genetic confirmation. The data were collected on a pre-established form then entered and analyzed with the following software: Excel 2013 and R version 4.1.3. Results: During our study period, 2100 children were hospitalized, the annual incidence was 0.76%. The average age of our patients was 9 ± 9 months with a range of 3 months to 32 months and the median was 6.5 months. The sex ratio was 7. The notion of family consanguinity was found in 62.5% of cases and the notion of ISA in the family in 25% of cases. Hypotonia and respiratory distress were found at the forefront in equal proportions (50% of cases). Electromyogram (EMG) was performed in 3 patients (37.5%). Symptomatic medical treatment was administered in 100% of patients, 04 patients had benefited from respiratory physiotherapy, i.e. 50% of cases, and genetic counseling was carried out in one patient (12.5%). The evolution was immediately favorable in 2 patients or 25% of cases, unfavorable in 75% of cases with a death rate of 50% and the average age of death was 5.5 months ± 1 with extremes ranging from 3 to 7 months. Conclusion: The number of Infantile spinal muscular atrophy cases remains low in hospitals in Dakar. Diagnostic means are still difficult to access. The course is difficult to predict and is often marked in the long term by respiratory difficulties which can be fatal.

Anesthetic Management of a Patient with Spinal Muscular Atrophy Type III Undergoing Emergent Caesarean Section: A Case Report

In this case report, we describe the anesthetic management for a 36-year-old G2P0010 at 36 weeks gestation with Spinal Muscular Atrophy Type III who underwent an emergent caesarean section due to fetal footling breech position. The patient is a wheelchair-bound quadriplegic with kyphoscoliosis and a lack of cough reflex who required nasal continuous noninvasive ventilatory support (CNVS) for chronic hypercapnic respiratory failure. Surgery was done under general anesthesia due to its emergent nature, and the patient was successfully extubated and transitioned to nasal CNVS in the operating room at the end of the case. Postoperative care was provided in the medical intensive care unit for three days without complication and the patient was discharged home uneventfully.

Autophagy inhibition: a new therapeutic target in spinal muscular atrophy

Spinal muscular atrophy（SMA）is a hereditary pediatric motor neuron（MN）disease：survival motor neuron 1（SMN1）gene mutation determines MN degeneration and,consequently,muscle atrophy,breathing and swallowing difficulties,and,in the most severe cases,premature death.A second unaffected gene（SMN2）is present,but it can only produce a limited amount of functional protein,modulating the disease severity and progression.

Emerging concepts underlying selective neuromuscular dysfunction in infantile-onset spinal muscular atrophy

Infantile-onset spinal muscular atrophy is the quintessential example of a disorder characterized by a predominantly neurodegenerative phenotype that nevertheless stems from perturbations in a housekeeping protein.Resulting from low levels of the Survival of Motor Neuron(SMN)protein,spinal muscular atrophy manifests mainly as a lower motor neuron disease.Why this is so and whether other cell types contribute to the classic spinal muscular atrophy phenotype continue to be the subject of intense investigation and are only now gaining appreciation.Yet,what is emerging is sometimes as puzzling as it is instructive,arguing for a careful re-examination of recent study outcomes,raising questions about established dogma in the field and making the case for a greater focus on milder spinal muscular atrophy models as tools to identify key mechanisms driving selective neuromuscular dysfunction in the disease.This review examines the evidence for novel molecular and cellular mechanisms that have recently been implicated in spinal muscular atrophy,highlights breakthroughs,points out caveats and poses questions that ought to serve as the basis of new investigations to better understand and treat this and other more common neurodegenerative disorders.

1000 sample comparison of MLPA and RT-PCR for carrier detection and diagnostic testing for Spinal Muscular Atrophy Type 1

Purpose: To compare the accuracy of a commercially available MLPA kit with a laboratory developed RT-PCR assay for the detection of SMN1 and SMN2 copy numbers in clinical samples. Methods: We developed and validated a laboratory developed real time PCR based test capable of detecting SMN1 and SMN2 copy numbers in individuals. We also validated an MLPA kit purchased from MRC Holland for the same purpose. We then analyzed a series of 1027 anonymized samples using both technologies. When discrepant results were obtained, each sample was re-analyzed at least twice using both platforms. Results: Five samples did not yield results in either assay. For SMN1 copy number analysis, 2 RT-PCR assays revealed indeterminant results and all 1020 other samples were concordant for SMN1 copy number. There were 9 discrepancies in SMN2 copy number determination mostly due to a variability in MLPA analysis. Conclusion: Both MLPA and RTPCR assays give a reliable estimate of SMN1 copy number and are therefore appropriate for population based carrier screening for Spinal Muscular Atrophy Type 1. The MLPA kit has a low incidence (<1%) of underestimating the SMN2 copy number by 1 copy, but this inconsistency is of little clinical significance and can be overcome by replicate testing.

Large deletions within the spinal muscular atrophy gene region in a patient with spinal muscular atrophy type 3

Spinal muscular atrophy （SMA） is an autosomal recessive neuromuscular disorder characterized by degeneration and loss of anterior horn cells in the spinal cord and brain stem nuclei, leading to progressive limb and trunk paralysis and muscular atrophy. Depending on the age of onset and maximum muscular function achieved, SMA is recognized as SMA1, SMA2, SMA3 or SMA4, and most patients have a deletion or truncation of the survival motor neuron 1 （SMN1） gene. In this report, we present a patient with a mild SMA phenotype, SMA3, and define his genetic abnormality. Tetra-primer amplification refractory mutation system PCR combined with restriction fragment length polymorphism analysis and array comparative genomic hybridization were used to determine the genetic variations in this patient. A 500 kb deletion in chromosome 5q13.2, including homozygous deletion of neuronal apoptosis inhibitory protein, and heterozygous deletion of occludin and B-double prime 1 was identified. This SMA region deletion did not involve SMN, indicating that SMN was likely to function normally. The phenotype was dependent of the large deletion and neuronal apoptosis inhibitory protein, occludin and B-double prime 1 may be candidate genes for SMA3.

Clinical features of adult spinal muscular atrophy:46 cases

BACKGROUND： Spinal muscular atrophy （SMA） is a kind of degenerative disease of nervous system. There are 4 types in clinic, especially types Ⅰ, Ⅱ and Ⅲ are common, and the researches on those 3 types are relative mature. Type IV is a kind of adult spinal muscular atrophy （ASMA）, which has low incidence rate and is often misdiagnosed as amyotrophic lateral sclerosis, muscular dystrophy, cervical syndrome, or others.OBJEETIVE： To observe the clinical features of 46 ASMA patients and analyze the relationship between course and activity of daily living. DESIGN ： Case analysis.SETTING： Departments of Neurology of the 81 Hospital of Chinese PLA, the Second Affiliated Hospital of Nanjing Medical College and General Hospital of Nanjing Military Area Command of Chinese PLA.PARTICIPANTS ： A total of 46 ASMA patients were selected from the Departments of Neurology of the 81 Hospital of Chinese PLA, the Second Affiliated Hospital of Nanjing Medical College and General Hospital of Nanjing Military Area Command of Chinese PLA between April 1998 and January 2002. All patients were consentient. Among 46 cases, there were 37 males and 9 females with the mean age of 42 years. The patients＇ courses in all ranged from 6 months to 23 years, concretely, courses of 37 cases were less than or equal to 5 years, and those of 9 cases were more than or equal to 6 years.METHODS： ① All the 46 ASMA patients were asked to check blood sedimentation, anti O, serum creatinine, creatine, blood creatine phosphokinase （CPK） and muscular biopsy as early as possible. ②X-ray was used to measure plain film of cervical vertebra borderline film of cranium and neck at proximal end of upper limb of 25 cases and plain film of abdominal vertebra at proximal end of lower limb of 17 cases. ③ Cerebrospinal fluid of lumbar puncture was checked on 42 cases, for routine examination, biochemical examination, and immunoglobulin examination. Electromyogram （EMG） was also examined to 42 cases. ④ Barthel index was used to evaluate activities of daily living （ADL） of patients with various courses. The index ranged from 1 to 100. The more the index of a ASMA was, the stronger his independence was. ⑤ The Barthel indexes of patients with courses ≤ 5 years and those ≥ 6 years were compared with univariate analysis of variance. MAIN OUTCOME MEASURES： ① Incidences of all patients at the first time; ② values of relative blood and blood biochemistry; ③results of muscular biopsy; ④ results of EMG and relative X-ray plain film of 42 cases; ⑤ results of cerebrospinal fluid of 42 cases; ⑥ comparisons of Barthel index of patients with various courses.RESULTS： A total of 46 ASMA patients were involved in the final analysis. ① Incidence on the first time： 25 patients had the disease at the proximal end of upper limb, 17 at the proximal end of lower limb, and 4 at the four limbs. ② Value of serum-blood CPK of one fourth patients was increased slightly （3.034-9.735 μkat/L; normal value： 0.400-3.001 μkat/L）, and other values of blood and blood biochemical indicator were normal. ③Results of muscle biopsy of all patients showed that a small group of muscular atrophy could be observed mostly, and muscle group in the same type and compensatory hypertrophy of muscle fibres were also observed with ATP enzyme staining. ④ Results of EMG of 42 cases suggested that 37 patients had mild and moderate nerve-derived injury and 3 had mild muscle-derived injury. Results of all the X-ray plain films in this study were normal. ⑤ Results of routine, biochemical and immunoglobulin examination in cerebrospinal fluid of lumbar puncture in 42 cases were all normal. ⑥The difference between Barthel indexes of patients with courses ≤ 5 years and those ≥ 6 years was not significant [（64.73±20.38） vs （68.89±21.76） points, P〉 0.05]. CONCLUSION ： ① Amyasthenia is mainly occurred at the proximal end of the four limbs of ASMA patients. A small group of muscular atrophy is its mostly pathological change, and the progression of the disease is slow. ② Most patients have mild and moderate nerve-derived injury under EMG examination.③ The duration of a patient suffered from the disease has no obvious effect on his ADL ability.

The Effects of Rufinamide on <i>in Vitro</i>Spinal Muscular Atrophy Model

Spinal muscular atrophy (SMA) is devastating genetic disease characterized by progressive loss of motor neuron and skeletal muscle weakness. SMA is the most common lethal genetic disease in infancy. SMA is caused by deletion or mutation of SMN1 gene and subsequent lack of SMN protein. Our purpose in this study was to evaluate the therapeutic potential of rufinamide, an antiepileptic drug. In this study, SMA patient-derived fibroblasts and differentiated spinal motor neurons (MNs) using SMA patient-derived iPSCs were used as in vitro SMA model. SMN mRNA was significantly increased by addition of rufinamide in type III SMA patient-derived fibroblasts. Furthermore, rufinamide stimulated neurite elongation in type III SMA patient derived-iPSCs-MNs. In contrast of the result using type III SMA patient-derived fibroblasts, the expression level of SMN mRNA was not changed after rufinamide treatment in type I SMA patient-derived fibroblasts, and rufinamide did not affect neurite outgrowth in type I SMA patients derived-iPSCs-MNs. These findings indicate that rufinamide may be one of the potential candidate drugs for mild type of SMA.

Nusinersen,an exon 7 inclusion drug for spinal muscular atrophy:A minireview

Spinal muscular atrophy is an autosomal recessive neuromuscular disease with incidence of 1 in 5000 to 10000 live births and is produced by homozygous deletion of exons 7 and 8 in the SMN1 gene.The SMN1 and SMN2 genes encode the survival motor neuron protein,a crucial protein for the preservation of motor neurons.Use of the newer drug,Nusinersen,from early infancy has shown improvement in clinical outcomes of spinal muscular atrophy patients.

Diagnosis of Progressive Spinal Muscular Atrophy by Using Polymerase Chain Reaction

Objective To understand the deletion in the survival motor neuron gene (SMN) of childhood onset spinal muscular atrophy (SMA) in Chinese, and the value of diagnosis of SMA using polymerase chain reaction restriction fragment length polymorphism (PCR RFLP)method. Methods\ Deletions of SMN gene of exon 7 and 8 in 10 cases of presumed SMA, and 20 normal controls from 6 families and 30 unrelated controls were performed by PCR RFLP analysis. Results\ Deletions of SMN gene detected in 9 of 10 (90%) cases of presumed SMA . No deletions of SMN in the telomere were found in the other members of families and controls.Conclusion\ PCR RFLP is a sensitive, specific and simple method in diagnosis of SMA.\;

成人脊髓性肌萎缩症(SMA)患者鞘内注射诺西那生钠注射液的围术期综合护理干预

目的探讨成人SMA患者行诺西那生钠鞘内注射治疗围术期的综合护理干预措施。方法总结12例成人SMA患者鞘内注射诺西那生钠注射液的围术期护理,分析、处理其围术期可能产生的一系列问题及观察其术后疗效。结果12例患者均顺利完成鞘内注射,术后未见明显并发症,如期出院,等待下一周期入院注射治疗。结论针对此类疾病围术期的综合有效护理干预,为后期更多患者的临床护理提供专业化的参考依据。

Electromyogram and pathological features of adult spinal muscle atrophy: analysis of 46 cases

AIM:To study the electromyogram and muscular pathological features of adult sp inal muscular atrophy(SMA4).METHODS:46 cases of SMA4 were evaluated based on cli nical,histopathology,enzyme histochemistry and ultrastructure.RESULTS:A mean age of the patients with SMA4 was 38.7 years,clinical progressed was slowly.Clinic manifestations mainly appeared proximal muscular weakness and progressive muscul ar atrophy,and there was a relatively good prognosis.Laboratory found:one-fourt h of the disease had elevated serum creatine kinase levels.Eletromyogram reveale d neurogenic damages. The muscular pathological changes showed small groups of a trophy of denervation,ATPase reaction showed fibre-type grouping of renervation and hypertrophy in muscle fibers.CONCLUSION:Muscle biopsy was important;it coul d to help to establish to diagnose the disorder and provided available cases for gene study.

SMA基因筛查和诊断技术的应用研究

目的:对10例中国人脊髓性肌萎缩症(SMA)家系进行基因诊断与产前诊断,为临床筛查、诊断SMA方法提供参考。方法:收集SMA家系患者及父母的临床资料、外周血和羊水样本,并提取DNA。应用荧光定量PCR(qPCR)检测基因突变型,应用多重连接探针扩增技术(MLPA)对其结果进行验证。结果:qPCR结果显示患者均为SMN1基因外显子7纯合缺失,父母均为7号外显子杂合缺失。MLPA结果显示患者均为SMN1基因7、8外显子纯合缺失,父母均为7、8外显子杂合缺失。羊水样本中,1例SMN1基因7、8外显子纯合缺失,2例SMN1基因7、8外显子杂合缺失,1例SMN1基因7、8外显子未见缺失。结论:qPCR检测方法简单、快速、经济,且结果稳定适合SMA的初步诊断和大规模人群筛查,结合MLPA,是临床的高效、经济且稳定的SMA基因诊断方法。

Insights into spinal muscular atrophy from molecular biomarkers

Spinal muscular atrophy is a devastating motor neuron disease characterized by severe cases of fatal muscle weakness.It is one of the most common genetic causes of mortality among infants aged less than 2 years.Biomarker research is currently receiving more attention,and new candidate biomarkers are constantly being discovered.This review initially discusses the evaluation methods commonly used in clinical practice while briefly outlining their respective pros and cons.We also describe recent advancements in research and the clinical significance of molecular biomarkers for spinal muscular atrophy,which are classified as either specific or non-specific biomarkers.This review provides new insights into the pathogenesis of spinal muscular atrophy,the mechanism of biomarkers in response to drug-modified therapies,the selection of biomarker candidates,and would promote the development of future research.Furthermore,the successful utilization of biomarkers may facilitate the implementation of gene-targeting treatments for patients with spinal muscular atrophy.

青少年成人脊髓性肌萎缩症高危人群快速识别方法的探索与展望

脊髓性肌萎缩症(SMA)是一种罕见的遗传性神经肌肉病,患者临床异质性较大。根据病情轻重和进展速度共分为5型。近年来随着多学科综合管理的推广和疾病修正治疗药物的应用,SMA患者的预后已明显改善,更多患者进入青少年及成人期。不同类型患者在青少年和成人期的状态各不相同,也使得这一年龄段患者表现更加复杂多样,识别与诊断更为困难。中国幅员辽阔、人口众多,不同地区医疗水平不均衡,进一步加剧了青少年及成人SMA患者的诊疗难题,误诊或诊断延迟仍是许多患者未解决的首要问题。患者就诊时首诊科室分布广泛,加强非神经肌肉病专科医生对青少年及成人SMA高危人群的识别具有重要意义。本文尝试探讨一种简单清晰、可操作性强的青少年成人SMA高危人群“画像”式识别方法,以期帮助可能首诊SMA患者的非神经肌肉病专科医生做到早期识别、早期诊断,使患者尽早获得规范治疗,从而进一步提高患者的临床获益,改善患者及其家庭的生活质量。

骨骼肌MRI在脊髓性肌萎缩症中的临床应用进展

脊髓性肌萎缩症(SMA)是一种发病率高并严重威胁儿童生命健康的遗传性神经肌肉疾病。MRI是神经肌肉疾病的主要影像检查方法,常规MRI能可视化肌肉形态学特征及病理改变,功能MRI能定量评估肌肉病变程度。骨骼肌MRI在评估SMA肌肉病变、治疗效果、吞咽功能及监测SMA进展中具有一定的临床价值。就骨骼肌MRI在SMA中的临床应用和研究进展进行综述。

利司扑兰单药治疗儿童脊髓性肌萎缩症随访1年的病例系列报告

背景利司扑兰服用1个月内对不同类型脊髓性肌萎缩症(SMA)患儿均有疗效,由于利司扑兰治疗获取的便捷性等原因复诊随访率较低,缺乏中国长期应用该药治疗的真实世界数据。目的观察不同类型SMA患儿利司扑兰单药治疗≥12个月的效果。设计病例系列报告。方法纳入2021年8月至2023年3月山东大学附属儿童医院神经内科门诊或住院、接受了利司扑兰初始和随访期间单药治疗的、治疗年龄≥16 d的、治疗开始和随访期间接受了运动功能评估的不同类型SMA的连续病例。依据利司扑兰说明书推荐的方法以年龄和体重计算口服剂量服药,观察随访≥6个月,由有评估资质的医生行运动功能评估,评估量表如下:费城儿童医院神经肌肉评估量表(CHOP INTEND)、修订的上肢模块测试(RULM)、汉默史密斯运动功能扩展量表(HFMSE)、6 min步行试验(6MWT),观察不良事件和发生率。主要结局指标运动功能改善水平(最后一次随访的运动功能评分-基线运动功能评分,或切换量表后最后一次随诊时运动功能评分)。结果14例SMA患儿进入本文分析,男9例(64.3%),女5例。除1例症状前患儿外,余13例患儿的平均起病年龄为9.0(3.0,12.0)月龄;14例SMA患儿接受利司扑兰治疗的平均年龄为19.5(6.5,39.5)月龄。1例SMN1拷贝数为1,存在点突变,余13例SMN1拷贝数均为0;SMN2拷贝数为1、2、3和4的患儿分别有1例、3例、9例和1例。症状前1例,1型6例,2型5例,3型2例。末次随访与首次给药时间间隔为20(11.8,25.5)个月。13例SMA患儿的运动功能改善具有临床意义,1例运动功能评分有提升,但改善尚不具临床意义。9例SMA患儿有基线及随访血常规、肝功能和肾功能结果;血常规均正常;2例基线时肝功能异常,随访中恢复正常;部分患儿血肌酐水平异常,与SMA疾病本身相关,随访中未见血肌酐水平增高。随访期间可能与药物无关的不良事件包括上呼吸道感染11例次,肺炎4例次,腹泻1例次,除1例肺炎为2型SMA,其余不良事件均发生于1型SMA;可能与药物相关的不良反应包括皮肤颜色改变12例(85.7%),皮疹2例(14.3%),便秘1例(7.1%)。未发现严重不良反应。本文报告了1例SMA患儿在出现症状前接受利司扑兰治疗可维持正常的运动功能发育的病例,也报告了SMN2单拷贝患儿接受利司扑兰同样具有良好效果。结论中国不同类型的SMA患儿长期接受利司扑兰单药治疗疗效尚好,常见不良事件为呼吸道感染和皮肤颜色改变。

脊髓性肌萎缩药物经济学评价的系统综述

目的综述脊髓性肌萎缩(SMA)药物经济学评价的研究新进展,以期为相关临床治疗、筛查和医保支付决策提供参考。方法计算机检索PubMed、Web of Science、Embase、Scopus、Cochrane Library、EBSCOhost、中国知网、维普、中国生物医学文献数据库、万方数据等数据库和英国国家健康研究所、国际卫生保健技术评估协会、美国医疗保健研究与质量局等卫生技术评估(HTA)机构的网站,搜集与SMA相关的药物经济学评价研究。检索时限为建库至2023年12月31日。由2名研究人员严格按照纳入、排除标准进行文献/报告筛选,并使用Excel 2019软件提取所纳入文献/报告的基本信息;采用卫生经济学评价报告标准共识2022评价纳入文献/报告的研究质量。结果最终纳入9篇文献和15篇HTA报告,文献的质量整体较好,但HTA报告的质量较差。SMA药物经济学评价研究共计24项,治疗方案包括诺西那生钠、索伐瑞韦、利司扑兰和最佳支持治疗等。综述结果显示,诺西那生钠治疗SMA不具有经济性;利司扑兰和索伐瑞韦等治疗方案的经济性尚无一致结论;新生儿/产前筛查联合药物治疗方案具有经济性。结论新生儿/产前筛查联合药物治疗SMA具有经济学优势。建议未来基于我国本土化参数和医保价格继续探讨SMA新型治疗药物与SMA筛查相关的经济性,逐步将SMA筛查纳入新生儿遗传病检测范围,从而缓解患者家庭和卫生体系沉重的经济负担。

超声引导下鞘内注射诺西那生钠治疗儿童脊髓性肌萎缩症

脊髓性肌萎缩症(spinal muscular atrophy, SMA)是以近端肢体进行性肌无力及肌萎缩为主要特征的常染色体隐性遗传病,多由5q13运动神经元存活基因(survival motor neuron gene, SMN)1突变或缺失导致,是儿童最常见的神经肌肉病^([1])。鞘内注射诺西那生钠为治疗SMA的有效手段,但对于脊柱严重侧凸者,常需于影像学引导下完成^([2-3])。

脊髓性肌萎缩症患者利司扑兰治疗药物监测方法研究

目的建立脊髓性肌萎缩症患者利司扑兰治疗药物监测的方法。方法采用超高效液相色谱串联质谱法,色谱柱为Phe‐nomenex Kinetex XB C18柱(50 mm×3 mm,2.6µm),流动相为0.07%甲酸水溶液(pH 4.5)-0.07%甲酸乙腈溶液(pH 5.5),梯度洗脱,流速为0.3 mL/min,柱温为40℃,进样量为2µL;采用电喷雾离子源(正离子模式),多反应监测模式,利司扑兰的离子对m/z分别为402.2→319.2、402.2→374.4,RG7800的离子对m/z为417.3→360.2。结果利司扑兰质量浓度在1.95~125.00 ng/mL范围内与其峰面积与内标峰面积比值线性关系良好(R2=0.9991,n=8),定量限为1.95 ng/mL;基质效应试验结果的变异系数均小于12%;精密度、稳定性试验结果的RSD均小于20%,准确度分别为87%~108%、87%~113%。6例患者利司扑兰血药浓度为13.03~91.14 ng/mL。结论该方法操作简便、高效快速,可用于脊髓性肌萎缩症患者利司扑兰的治疗药物监测。