中国汉族人群CACNA1A基因CAG重复数目分布特点及其在脊髓小脑性共济失调6型基因诊断中的应用

目的 探讨我国汉族人群CACNA1A基因CAG重复数目分布特点及其在脊髓小脑性共济失调6型(spinocerebellar ataxias type 6,SCA6)基因诊断中的应用.方法 应用"两步PCR法"、变性聚丙烯酰胺凝胶电泳(DPAGE)和测序等方法对300名健康对照及109例无血缘关系的SCA患者进行CACNA1A基因CAG三核苷酸重复数目分析.结果 300名健康对照的CAG重复次数范围为3～18次,以13次最常见.在109例SCA患者中,发现1例SCA6患者,其CAG异常重复次数为24次,该患者的母亲和哥哥亦为SCA6患者,临床上均表现为缓慢进展的小脑性共济失调、构音障碍、眼震、轻度的振动及本体觉减退,遗传早现现象较明显.结论 SCA6病例在我国较少见,进行CACNA1A基因突变分析有助于临床诊断."两步PCR法"可提高CACNA1A基因突变分析的效率.     

遗传性脊髓小脑型共济失调患者SCA1基因突变检测分析

检测中国人遗传性脊髓小脑型共济失调（ＳＣＡ）患者的ＳＣＡ１基因突变［（ＣＡＧ）ｎ］。方法应用聚合酶链（ＰＣＲ）技术，检测了２７个ＳＣＡ家系中４４例ＳＣＡ患者的ＳＣＡ１（ＣＡＧ）ｎ。结果首次发现１个家系２例患者及１位“正常者”均有１个ＳＣＡ１异常等位基因扩增片段。患者Ⅲ５与其１位兄弟（“正常者”）的异常等位基因扩增片段，长度为２７２ｂｐ，三核苷酸ＣＡＧ重复数为５３次，患者Ⅲ２的异常等位基因扩增片段，长度为２９９ｂｐ，ＣＡＧ重复数为６２次，均超出正常范围。另２６个家系４２例患者的等位基因扩增片段长度范围在１６４～２１８ｂｐ之间，ＣＡＧ重复数在１７～３５次间，属于正常范围。结论来自１家系２例ＳＣＡ患者的基因分型为ＳＣＡ１型，“正常者”可能是未到发病年龄的无症状ＳＣＡ１患者，余２６个家系４２例患者不是ＳＣＡ１型。     

食蟹猴脊髓小脑性共济失调模型的制作研究

目的 探讨食蟹猴脊髓小脑性共济失调(SCAs)模型的制作. 方法选取2只成年雄性食蟹猴,在不同的时间段内分别采用腹腔注射3-乙酰吡啶(3-AP)、静脉注射3-AP及立体定向注射3-AP损毁小脑中央核群(顶核、齿状核、栓状核)的方法制作食蟹猴SCAs模型,并建立行为学评价体系(行为学评定、取食实验、水平旋转实验等)用于食蟹猴共济运动的评估. 结果首先采用腹腔注射3-AP 8倍有效剂量并观察12周,行为学评价体系结果未出现有关共济失调的症状;再次采用静脉注射3-AP6倍的有效剂量并观察12周,行为学评价体系结果未出现有关共济失调的症状;最后立体定向注射3-AP损毁小脑中央核群,行为学评价体系结果统计分析显示造模后8周内均较造模前差异有统计学意义(P<0.05),而造模后12周起又逐步恢复至造模前状态. 结论立体定向注射3-AP损毁小脑中央核群方法可以制作食蟹猴SCAs的急性模型,行为学评定、取食实验、水平旋转实验适用于该模型的评价.     

三核苷酸重复的检测在脊髓小脑型共济失调的应用研究

目的建立中国人遗传性脊髓小脑型共济失调（ＳＣＡ）患者的ＳＣＡ１、ＳＣＡ２、ＳＣＡ３／ＭＪＤ、ＳＣＡ６型的ＣＡＧ三核苷酸重复（ＣＡＧ）ｎ频率的检测方法并探讨其诊断意义。方法应用聚合酶链式反应（ＰＣＲ）和６％变性聚丙烯酰胺凝胶电泳技术,检测了３０例正常人和６例临床诊断为ＳＣＡ患者上述４型的（ＣＡＧ）ｎ重复数。结果３０例正常人（ＣＡＧ）ｎ的重复数目分别为ＳＣＡ１６～４０次,ＳＣＡ２２２～２９次,ＳＣＡ３１３～３６次,ＳＣＡ６４～１６次。６例ＳＣＡ患者中２例有ＳＣＡ３异常,（ＣＡＧ）ｎ重复数分别为６７和７５,而ＳＣＡ１、ＳＣＡ２、ＳＣＡ６型（ＣＡＧ）ｎ重复数均在正常范围内。结论研究三核苷酸重复频率的检测为ＳＣＡ患者提供了准确可靠的诊断方法和标准。     

遗传性小脑共济失调的多形式诱发电位研究

研究遗传性小脑共济失调的诱发电位变化。方法采用多种形式诱发电位，对３６例此类疾病的患者进行检测，并与３０～４０名健康者作对比。结果全部患者至少存在１种以上的诱发电位异常。磁刺激运动诱发电位（ＭＥＰ）、脑干听觉诱发电位（ＢＡＥＰ）及胫后神经与正中神经体感诱发电位（ｔＳＥＰ、ｍＳＥＰ）的异常率分别为８３．３％、８８．９％、８０．０％和６２．５％。不同类型小脑共济失调的诱发电位异常率不同，各型ＢＡＥＰ的异常率普遍较高，橄榄－桥脑－小脑萎缩患者的ＭＥＰ与遗传性痉挛性共济失调的ｔＳＥＰ异常率也很高。ＭＥＰ测试时，刺激皮质在患者中所记录到的双峰波、多相波以及波宽增加，表明皮质运动神经元的异常放电。结论多形式诱发电位改变应列为慢性小脑变性分类学上的诊断依据     

Identification of early neurodegenerative change in presymptomatic spinocerebellar ataxia type 1: A diffusion tensor imaging study

We report a 41-year-old man of presymptomatic spinocerebellar ataxia type 1. Diffusion tensor imaging (DTI) verified decreased fractional anisotropy of cerebellar afferent and efferent pathways compared to 5 age-matched healthy controls while conventional MRI revealed normal brain. DTI was valuable in detection of early microstructural damage of cerebellar pathways.     

Estimation of skeletal muscle mass in patients with spinocerebellar ataxia type 3 and 10

Background: Neurodegenerative diseases may progress to a level in which patients present spontaneous weight loss, resulting in increased falls and functional disabilities when the disease is associated with muscle mass depletion.

Objective: Evaluate the muscle compartment in patients presenting spinocerebellar ataxia (SCA) type 3 and 10.

Methods: Forty-six patients presenting SCA type 3 and 10 were assessed and 76 volunteers were selected to the control group. In order to evaluate the muscle compartment, muscle mass anthropometric measurements were assessed and total skeletal muscle mass calculated through a predictive equation.

Results: Women with SCA3 presented greater weight loss and muscle mass reduction compared to those with SCA10 and the control group. Among the predictive measurements, calf muscle circumference showed a more significant correlation with total skeletal muscle mass (p = 0.718).

Conclusion: Patients presenting both types of ataxia did not show severe depletion in their nutritional status; however, those with SCA3 displayed greater weight loss and muscle mass reduction compared to the SCA10 group.     

细胞凋亡在脊髓小脑性共济失调3型发病机制中的作用

目的研究细胞凋亡在脊髓小脑性共济失调3型(SCA3)分子发病机制中的作用。方法将带有SCA3正常与突变基因的增强型绿色荧光蛋白真核表达载体(pEGFP)转染大鼠肾上腺嗜铬细胞瘤(PC12)细胞,采用丫啶橙(AO)染色及电镜观察细胞凋亡的发生情况,免疫荧光检测转染后24h、72h、120h半胱氨酸天门冬氨酸酶3、8(caspase3、8)在细胞核内的分布及其与核内包涵体(INIs)共定位的情况;缺口末端标记(TUNEL)法观察正常基因组与突变基因组以及突变基因组在给予广谱caspase阻断剂zVAD-fmk(100μmol/L)后细胞凋亡的变化。结果随着转染后时间的延长,突变基因组细胞发生了明显的凋亡,caspase3、caspase8核内与INIs共定位。正常组与突变组TUNEL阳性细胞数有明显差异并有显著性意义(P<0.01),突变组在给予zVAD-fmk后细胞凋亡明显减轻,差异有显著性意义(P<0.01)。结论细胞凋亡在SCA3发病机制中起重要的作用,抑制凋亡通路可以减少细胞死亡,推测对凋亡环节的干预有可能成为SCA3治疗的靶点。     

广东汉族人遗传性脊髓小脑型共济失调基因突变的研究

目的 研究广东汉族人遗传性脊髓小脑型共济失调（SCA）的亚型（SCA1、SCA2、SCA3和SCA7）基因突变分布频率。方法 对临床诊断为SCA的18个家系24例SCA患者、22例散发SCA患者、45名家系“正常人”及30名非家系健康人,通过聚合酶链反应（PCR）及聚丙烯酰胺凝胶电泳（PAGE）等技术检测SCA1、2、3、7基因内CAG三核苷酸重复序列突变,并利用ABI310、377测序仪对异常等位基因片段进行DNA测序。结果 在18个SCA家系中,1个家系（5.55％）有SCA1基因突变,2个家系（11.11％）有SCA2基因突变,7个家系（38.88％）有SCA3基因突变,未发现SCA7突变,。在家系成员中检出1例症状前SCA3患者。22例散发性患者中检出SCA1、SCA2、SCA3和SCA7各1例,各占4.54％。SCA1患者CAG重复数为53～56次,正常人19～34次;SCA2患者CAG重复数为38～45次,正常人20～25次;SCA3患者CAG重复数为74～81次,正常人14～40次。SCA7患者CAG重复数为65次,正常人为9～19次。结论 提示中国人SCA主要为SCA3/MJD型,其次为SCA2和SCA1。基因分析对家族性以及散发性SCA患者的临床确诊和遗传咨询均有重要意义。     

CT scan and threshold vibrometry in the diagnosis of spinocerebellar degenerations

45 patients with spinocerebellar degeneration (SCD) underwent through quantitative investigation of the ventricular and cisternal systems by CT scanning and threshold vibrometry in the limbs to find out whether these parameters could be used for distinguishing mainly spinal from cerebellar forms or from olivopontoce-rebellar atrophy. The increase in the vibration sense threshold and the mild atrophy in the posterior cranial fossa proved typical of spinal forms and the reverse for cerebellar forms. In olivopontocerebellar atrophy enlargement of the cisterns and dilatation of the ventricles always exceeded 85% of normal values.

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Sommario 45 pazienti affetti da degenerazione spinocerebellare (SCD) sono stati sottoposti ad uno studio approfondito di esplorazione quantitativa del sistema ventricolare e cisternale alla TAC e della soglia di percezione vibratoria agli arti per valutare la possibilità di distinguere con questi parametri le forme prevalentemente spinali da quelle cerebellari o delle atrofie olivopontocerebellari. L'aumento della soglia vibratoria e la modesta atrofia in fossa posteriore è risultata tipica delle forme spinali, mentre l'inverso si verifica per le forme cerebellari. Nelle atrofie olivopontocerebellari l'allargamento delle cisterne e la dilatazione dei ventricoli supera quasi sempre l'85% rispetto ai casi normali.

     

Spinocerebellar ataxia type 6 in eastern India: Some new observations

Introduction:Spinocerebellar ataxias (SCAs) are hereditary, autosomal dominant progressive neurodegenerative disorders showing clinical and genetic heterogeneity. They are usually manifested clinically in the third to fifth decade of life although there is a wide variability in the age of onset. More than 36 different types of SCAs have been reported so far and about half of them are caused by pathological expansion of the trinucleotide, Cytosine Alanine Guanine (CAG) repeat. The global prevalence of SCA is 0.3-2 per 100,000 population, SCA3 being the commonest variety worldwide, accounting for 20-50 per cent of all cases, though SCA 2 is generally considered as the commonest one in India. However, SCA6 has not been addressed adequately from India though it is common in the eastern Asian countries like, Japan, Korea and Thailand.Objective:The present study was undertaken to identify the prevalence of SCA6 in the city of Kolkata and the eastern part of India.Results:6 of the 83 subjects turned out positive for SCA6, constituting therefore, 13.33% of the patient pool.Discussion:SCA6 is prevalent in the eastern part of India, though not as frequent as the other common varieties.Conclusions:Further community based studies are required in order to understand the magnitude of SCA6 in the eastern part, as well as in other regions of India.     

脊髓小脑性共济失调3型一家系的临床表现分析

目的 探讨1个脊髓小脑性共济失调3型(SCA3)家系中患者的临床表现,分析影响其特征、异质性及严重程度的原因。方法 采用PCR、琼脂糖凝胶电泳的方法对1个脊髓小脑性共济失调家系进行基因检测明确分型并获得等位基因内CAG三核苷酸重复扩增次数; 对比该家系中5例患者的典型症状、非典型症状,了解其临床异质性并分析产生原因。结果 确定该家系为脊髓小脑性共济失调SCA3型,发现3名表现正常的女性携带者。CAG重复次数与病程长短呈负相关(r=-0.942,P<0.05); 病程与共济失调严重程度呈正相关(r=1.000,0.913,P<0.01)。结论 该家系所有患者以明显共济失调及构音障碍为临床特征,特别是躯干及下肢的共济失调; CAG重复次数、病程及共济失调严重程度之间有明显相关性; 认知功能障碍随着疾病的进展逐渐显现; 眼肌麻痹、括约肌功能障碍或吞咽困难与CAG重复次数之间无明显关系但增加疾病持续时间; 锥体束受损及严重程度可能提示预后不良。     

Spinocerebellar projections from the central cervical nucleus in the cat, as studied by anterograde transport of wheat germ agglutinin-horseradish peroxidase

The projection of the spinocerebellar tract arising from the central cervical nucleus with crossed ascending axons was studied by the anterograde transport of wheat germ agglutinin conjugated to horseradish peroxidase (WGA-HRP) in the cat. Following injections of WGA-HRP into the C1 to the C4 or C5 segments, labeled terminals were seen in lobules I-VI, sublobule VIIb, lobules VIII and IX, the paramedian lobule, crus I and crus II, and the simple lobule. About 67-80% of the total number of labeled terminals were in the anterior lobe and 20-33% in the posterior lobe; the labeled terminals were abundant in lobules I (11-20%), II (11-28%), III (5.7-9.6%), IV (8.6-15.4%), and VIII (9-12%). The labeled terminals were densely distributed in the basal half or basal two-thirds of sublobules IIa-Va and VIf-VIb in their apicobasal extent and the transitional areas between neighboring sublobules. In sublobules Ia, Ib, and Vg they were distributed over the entire sublobule. The labeled terminals were most abundant within 0.5 mm of the midline (30-55% of the total number in each sublobule). Results in cases with injections into the C2-C4 segments, preceded by hemisection between the C1 and C2 segments, revealed that the projections were bilateral but predominantly contralateral to the cells of origin; the proportion of the quantity of the contralateral projection to that of the ipsilateral was about 60:40% in sublobules Ia-Vb and sublobules Ve-Vg. The projection field in the horizontal plane of the lobule was reconstructed from a series of cross sections through each sublobule. The labeled terminals were distributed in three major longitudinal areas named areas 1, 2, and 3, respectively. These areas were confined in the basal half to two-thirds of lobules III-V: area 1 located in zone A1 of Voogd (within 0.25 mm of the midline); area 2 located in zones A1 to A2 (at around 0.5 mm lateral to the midline); and area 3 located in the lateral part of zone A2 to zone B (between 0.75 mm and 1.5 mm lateral to the midline in lobule III, and between 1.0 mm and 2.0 mm lateral to the midline in lobules IV-VI). An indefinite area 4 appeared in zones B and C of some lobules. In sublobules Ia, Ib, Vf, and Vg the three areas extended throughout the apicobasal length.(ABSTRACT TRUNCATED AT 400 WORDS)     

脊髓小脑性共济失调3型一家系报道

目的 探讨脊髓小脑性共济失调(spinocerebellar ataxia, SCA)3型(SCA3)的临床特点。方法 收集1例2016年6月在济宁医学院附属医院神经内科住院的SCA3患者及其家系的临床资料,基因检测明确家系分型,结合文献分析家系中的临床差异。结果 患者23岁发病,临床表现为行走不稳伴进行性下肢无力,肌张力正常,水平性诱发眼震,无跌倒及吟诗性语言,闭目难立征阳性,呈宽基底步态,双侧巴氏征未引出,腹壁反射减低,膝反射及跟腱反射活跃,深浅感觉未见异常。基因检测提示患者ATXN3基因CAG重复次数79次(正常人范围在12～44次),超过正常范围,患者其它(ATXN1、ATXN2、CACNA1A、ATXN7、ATXN8、PPP2R2B、TBP)基因的CAG重复次数均在正常范围内。患者的55岁父亲、6岁女儿及4岁儿子的ATXN3基因的CAG重复数分别为65、73、71次,超过正常范围,但均未发病。患者母亲ATXN3基因的CAG重复数29次,属正常范围,未见临床症状。结论 本例家系是SCA3型,具有临床异质性,基因检测有助于诊断。     

Family history as a clue to the diagnosis of orofacial abnormal movements in a 30-year-old man

A 30-year-old man presented with a two-year history of involuntary movements in the face and mouth. Movements progressively worsened during the previous six months. Born from non-consanguineous parents, he had normal developmental milestones and his past medical history was unremarkable. The patient did not take any medication or had a history of illicit drug use. Family history was positive for unsteady gait of unknown cause. Neurological examination disclosed isolated orofacial dystonia affecting the face, particularly his mouth and eyes, resembling Meige’s syndrome. Dystonic closure of eyelids and dystonic contractions of orbicularis oris and platysma were particularly visible while patient was talking. The Montreal Cognitive Assessment score was 30. There were no other movement disorders or other abnormalities in neurological examination. Of note, cerebellar examination as well as gait assessment were normal.     

脊髓小脑共济失调7型一个家系的临床和基因分析

目的总结脊髓小脑共济失调7型（SCA7）的临床表现，开展基因检测。方法对1个表现为视力下降、辨色力异常和行走不稳的家系完成家系调查及体格检查，部分成员行视网膜形态学及电生理检查；19名家系成员及12名健康对照者行SCA7突变基因PCR，测序仪直接检测三核苷酸胞嘧啶-腺嘌呤-鸟嘌呤（CAG）重复数目。结果6例成员存在小脑性共济失调、视力下降和辨色力异常，眼底示黄斑及视网膜周边色素异常，视网膜电图波形熄灭，震荡电位幅值和光闪视觉诱发电位振幅明显下降；正常等位基因CAG重复数目为8～25次，该6例异常等位基因CAG重复数目为50～97次，诊断为SCA7患者；1例无异常临床表现的成员CAG重复数目分别为18次和56次，后者超出正常范围，诊断为未到发病年龄的症状前患者。结论SCA7患者的临床表现具有异质性，CAG重复数目检测可以为基因诊断和症状前诊断提供依据。     

Autosomal dominant cerebellar ataxia type I in Morocco: presence of the SCA1 and SCA3/MJD mutations

We searched for CAG repeat expansions at the SCA1 and SCA3/MJD loci in nine families, including 15 examined patients, with autosomal dominant cerebellar ataxia type I from Morocco. Expansion of the CAG repeat was found in one family at the SCA1 and two at the SCA3/MJD locus, demonstrating the existence of genetic heterogeneity among ADCA type I families in Morocco. Instability during transmission was observed at both loci as in other unstable mutations. The phenotypes of the SCA1 and SCA3/MJD patients were similar.     

一家系4代9例脊髓小脑性共济失调临床特征与基因检测分析

目的通过对一家系4代9例脊髓小脑性共济失调(SCA)患者的临床特征和部分患者的基因测序分析,为临床诊断提供依据。方法通过先证者建立家系图谱,收集患者的发病年龄、主要症状、持续时间和死亡患者的年龄,建立该家系患者的临床特征;通过聚合酶链反应(PCR)技术检测先证者和其无症状女儿的SCA1、SCA2、SCA3、SCA6、SCA7、SCA12和齿状核-红核-苍白球-丘脑路易斯核萎缩(DRPLA)的三核苷酸重复序列的数目,确立其遗传类型。结果该家系4代9例患者,第Ⅰ代发病年龄55岁,死亡60岁;第Ⅱ代发病年龄50岁,死亡60岁;第Ⅲ代发病30～47岁,死亡60岁;第Ⅳ代发病20岁。主要症状均为走路不稳和语言含糊不清,从发病到死亡的持续时间1～30年;基因测序表明先证者SCA3相关基因的CAG重复数目20/73,其女儿为15/78;其余SCA1、SCA2、SCA6、SCA7、SCA12、DRPLA基因测序均在正常范围内。确诊为SCA3。结论基因测序可以帮助确诊SCAs和无症状患者。