贵州少数民族遗传性痉挛性截瘫患者spastin基因突变的研究

目的 研究贵州地区少数民族遗传性痉挛性截瘫(HSP)患者spastin基因突变的特征.方法 应用PCR产物直接DNA测序法,对贵州16例少数民族(布依、苗、彝族)HSP患者(其中14例患者来自3个常染色体显性遗传家系,2例散发患者)spastin基因的8、10、14号外显子进行分析.将测序结果与人类基因组SPG4基因序列进行比对.结果 16例患者的spastin基因8、10、14号外显子直接DNA测序结果均未发现有突变.结论 贵州少数民族HSP患者spastin基因8、10、14号外显子的突变可能较少见,其与汉族HSP患者的spastin基因突变形式可能不同.     

遗传性痉挛性截瘫spastin、atlastin和paraplegin基因突变分析

目的探讨遗传性痉挛性截瘫(HSP)spastin、atlastin和parap legin基因的突变特点。方法应用聚合酶链反应-单链构象多态性(PCR-SSCP)结合DNA序列分析方法对24个常染色体显性遗传HSP家系和14例散发患者进行spastin基因和atlastin基因突变分析;对12个常染色体隐性遗传HSP家系和14例散发患者进行parap legin基因突变分析。结果在5个不同的常染色体显性遗传HSP家系中发现4个spastin基因新突变(1223 insCTCA、1258T→A,1293A→G和1668delCTA),在2例散发患者中发现2个spastin基因多态(IVS1-31C→G和IVS2-47A→G);在常染色体显性遗传HSP家系和散发患者中未发现atlastin基因突变或多态;在常染色体隐性遗传HSP家系和散发患者中未发现致病突变,仅在2例散发患者中发现2个parap legin基因多态(2063G→A及2066G→A)。结论我国遗传性痉挛性截瘫患者中spastin基因突变较常见,atlastin和parap legin基因的突变率可能较低。     

遗传性痉挛性截瘫的分子遗传学进展

遗传性痉挛性截瘫 (hereditaryspasticparaplegia ,HSP或SPG) ,又称Str櫣ｍｐｅｌｌ Lorrain病 ,是一组具有明显临床和遗传异质性的神经系统变性疾病 ,按临床表现可分为单纯型和复杂型 ,单纯型只表现为进行性双下肢肌张力增高和无力 ,合并脊髓外损害 ,如肌肉萎缩、精神发育迟滞、共济失调、多发性神经病、视神经萎缩、视网膜色素变性、耳聋、锥体外系等症状的称为复杂型 ;按遗传方式分为常染色体显性遗传(AD)、常染色体隐性遗传 (AR)和X 连锁隐性遗传 (XR)。据统计 ,HSP的患病率为 2 0 / 1 0万至 9 6/ 1 0万[1 ] 。近年来 ,本病的…     

遗传性痉挛性截瘫的病理、遗传学、发病机制和临床的研究进展

遗传性痉挛性截瘫(HSP或SPG),又称为Str櫣mpell-Lor-rain病,是一种具有临床及遗传异质性的神经系统遗传病,表现为缓慢进展的双下肢无力及痉挛性截瘫。根据HSP临床特征的不同分为两型,即单纯型及复杂型。单纯型HSP表现为逐渐进展的双下肢痉挛、步态不稳、键反射亢进,可以合并膀胱括约肌功能障碍;复杂型HSP除了上述临床表现外还可伴有智力障碍、锥体外系症状、共济失调、癫癎、白内障、视神经萎缩、视网膜变性、鱼鳞病及周围神经病等;根据遗传方式不同HSP可分为常染色体显性遗传(AD)、常染色体隐性遗传(AR)和X-连锁隐性遗传(XR),其…     

遗传性痉挛性截瘫患者MJD1基因的突变分析

目的探讨中国汉族人群中遗传性痉挛性截瘫(Hereditary Spastic Paraplegia,HSP或SPG)患者的MJD1基因突变特点,进一步探索HSP和遗传性脊髓小脑性共济失调(Spinocerebellar Ataxia,SCA)的遗传和临床异质性。方法应用聚合酶链反应、8%变性聚丙烯酰胺凝胶电泳和DNA T载体连接测序等方法对78例临床诊断为HSP的患者进行MJD1基因突变分析。结果在18个HSP家系中检出SCA3/MJD1家系2个,占11.1%,该2例家系均为常染色体显性遗传,2例家系先证者在临床上符合HSP的诊断标准,突变的MJD1等位基因CAG三核苷酸异常重复次数分别为65和69次,散发的HSP病例未发现MJD1等位基因的异常。结论HSP和SCA都具有明显的临床和遗传异质性,其表型在临床上有相互交叉现象,部分SCA3/MJD1患者临床上可为典型的痉挛性截瘫特征而无任何明显的共济失调表现。对临床表现为HSP的患者,尤其是有明显阳性家族史的患者进行MJD1基因诊断可以弥补HSP临床诊断的不足。     

Huntington病的临床和遗传特征

目的 探讨Huntington病(HD)的临床和遗传特征.方法 对6个中国汉族HD家系28例患者的临床资料和遗传特征进行回顾性分析.结果 本组男15例,女13例;起病年龄26～72岁;病程6～20年;有基因携带者6例(男2例,女4例);均以进行性加重的舞蹈样不自主运动为主,伴精神异常3例,痴呆1例,共济失调3例,晚期出现吞咽及构音障碍10例.1例基因携带者头颅磁共振波谱(MRS)分析显示两侧豆状核出现较明显的Lac倒置峰.6个家系均呈常染色体显性遗传,基因诊断发现受测患者和无临床表现的基因携带者均有(CAG)n重复拷贝数超过正常值(≥37);本组中有4个家系子代较父代发病年龄提前.结论 HD临床表现多样化,是一种常染色体显性遗传的神经变性疾病,存在遗传早现现象.IT15基因中(CAG)n重复拷贝数的异常扩展是这6个家系发生HD的发病基础.     

遗传性痉挛性截瘫的临床和遗传特点

目的：探讨遗传性痉挛性截瘫的临床和遗传特点。方法：对39个家系113例患者的临床资料进行回顾性分析。结果：男：女为1：1.17，发病年龄2-58岁，平均21.4岁，30例以前发病占81.7％。有家族史者占89.4％，多呈常染色体显性遗传。近亲结婚家系占28.2％。单纯型24例，复杂型89例。双下肢肌力下降占65.5％，肌张力增高和腱反射亢进均为96.5％，病理征阳性68.1％。合并症中共济失调占46.9％，肌萎缩占32.7％，痴呆占18.6％。结论：本组遗传性痉挛性截瘫患者多于青少年或青年发病，女性多于男性，复杂型较单纯型多见，遗传方式以常染色体显性遗传多见，近亲结婚明显增加该病的发生。     

常染色体显性遗传的遗传性痉挛性截瘫一家系的临床特点与致病基因排除定位分析

遗传性痉挛性截瘫（SPG）是一组具有明显临床和遗传异质性的神经系统遗传病，患病率2．0／10万～9．6／10万。按临床表现可分为单纯型和复杂型；按遗传方式分为常染色体显性遗传（AD）、常染色体隐性遗传（AR）和X-连锁隐性遗传（XR），其中以AD遗传最为常见。我们诊断1个AD遗传的SPG家系，对该家系临床特点和致病基因进行了排除定位分析，报道如下。     

遗传性痉挛性截瘫患者179例的临床与遗传学特点

目的 探讨我国遗传性痉挛性截瘫(HSP)患者的临床与遗传学特点.方法 对179例中国汉族人群HSP患者的临床资料和遗传学特点进行回顾性分析.结果 共收集78个家系114例患者和65例散发患者,家族史阳性率为54.5%,未发现遗传早现现象,部分家系存在外显不全.患者中男女比例为1.84:1,平均发病年龄(18.1±14.0)岁,平均病程(12.3±11.5)年;常染色体显性遗传(AD)-HSP患者的发病年龄[(19.7±14.0)岁]较常染色体隐性遗传(AR)-HSP者[(14.5±8.8)岁]大(t=2.196,P＜0.05),病程较AR-HSP者长[分别为(17.9±14.4)年和(8.0±5.8)年,t=4.404,P＜0.01].单纯型79例,复杂型100例;AD-HSP以单纯型为主,AR-HSP以复杂型为主,两者构成比差异有统计学意义(F=19.322,P＜0.01).患者多以双下肢僵硬、不灵活起病,最常见的体征为双下肢腱反射亢进、肌张力增高和病理征阳性,其次为踝阵挛(46.9%)、双下肢肌力下降(42.5%)、足部畸形(30.7%)等;AR-HSP患者共济失调、构音障碍、智能减退和足部畸形较AD-HSP多见,泌尿系统症状较AD-HSP少见(P＜0.05).65例患者行颅脑MRI检查,发现胼胝体发育不良13例(20.0%)、小脑萎缩9例(13.8%);45例患者行脊髓MRI检查,发现脊髓变细7例(15.6%).结论 本组HSP患者多于青少年期起病,男性多于女性.AD-HSP发病晚、病程长,以单纯型为主,更易出现泌尿系统症状;AR-HSP发病早、病程相对短,以复杂型多见,多伴有共济失调、构音障碍及智能减退,影像学改变以胼胝体发育不良多见;该病存在与性别相关的临床异质性,存在"女性保护"现象.     

遗传性脊髓小脑型共济失调7型临床特征及基因突变分析

目的分析中国汉族人群ATXN7基因突变,探讨遗传性脊髓小脑型共济失调7型（SCA7）患者临床特征。方法运用聚合酶链反应、变性聚丙烯酰胺凝胶电泳和毛细管电泳方法对521例临床诊断为SCA的患者（337例常染色体显性遗传先证者,184例散发患者）及258名健康对照人群进行ATXN7基因CAG三核苷酸重复突变分析,并对有ATXN7基因异常的7个家系进行临床总结。结果337例常染色体显性遗传先证者中发现7个ATXN7基因CAG三核苷酸异常重复扩增突变（2.08%）,其异常重复次数范围为38～71次;184例散发患者未发现CAG三核苷酸异常重复扩增突变。258名健康对照者中共发现13种等位基因,CAG重复次数范围为5～17次,平均10.23次,以10次CAG三核苷酸重复最常见。7个SCA7家系临床主要表现为共济失调、视力下降、眼底病变,同时可合并其他多种少见临床症状,在父系遗传时存在明显的遗传早现现象。结论SCA7多呈常染色体显性遗传,散发病例罕见,临床表现复杂,进行ATXN7基因突变分析有助于临床诊断。     

Autosomal dominant cerebellar ataxia: frequency analysis and clinical characterization of 45 families from Portugal

Background and purpose:  The relative frequency of the different autosomal dominant cerebellar ataxia (ADCA) varies widely amongst different geographic locations. Here we describe a series of 45 ADCA families from Portugal.
Methods:  Patients with progressive cerebellar dysfunction of autosomal dominant transmission underwent a clinical examination protocol and genetic testing for spinocerebellar ataxia (SCA)1 to Machado-Joseph disease (MJD)/SCA3, SCA6, SCA7, SCA10, SCA12, SCA17 and dentatorubral-pallidoluysian atrophy (DRPLA). We registered the clinical characteristics and frequency of each type of ataxia.
Results:  MJD/SCA3 was the most frequent ADCA (26 families, 57.8% of all families), followed by DRPLA (5 families, 11.2%), SCA7 (2 families, 4.4%), SCA2 and SCA1 (1 family each, 2.2% each); 10 families (22.2%) had no molecular diagnosis. SCA1 and SCA7 patients had African ancestry. DRPLA patients had Portuguese ancestry and were characterized by prominent anticipation and a variable combination of epilepsy, extra-pyramidal symptoms and dementia. Ophtalmoparesis, slow saccades and retinopathy were most distinctive of SCA3, SCA2 and SCA7 cases, respectively.
Conclusions:  MJD/SCA3 was the most common ADCA in this group of families. The high frequency of DRPLA and presence of SCA1 and SCA7 cases was unexpected. The presence of these rarer ADCA types probably reflects migration phenomena, posing a challenge for differential diagnosis.     

DRPLA: An unusual disease or an underestimated cause of ataxia in Brazil?

BackgroundDentatorubral-pallidoluysian atrophy (DRPLA) is a rare autosomal dominant spinocerebellar ataxia caused by pathological expansion of CAG trinucleotide repeats in the ATN1 gene. Most cases were described in patients from Japanese ancestry who presented with adult-onset progressive cerebellar ataxia associated with cognitive impairment, choreoathetosis and other movement disorders. DRPLA has been rarely described in Brazilian patients.MethodsWe performed a retrospective observational multicentric study including six different Neurology Centers in Brazil. All patients with genetically confirmed diagnosis of DRPLA had their medical records evaluated and clinical, genetic and neuroimaging features were analyzed.ResultsWe describe of eight Brazilian patients (5 male, 3 female) from four nuclear families with genetically confirmed DRPLA. The most common neurological features included cerebellar ataxia (n = 7), dementia (n = 3), chorea (n = 2), psychiatric disturbances (n = 2), progressive myoclonic epilepsy (n = 2) and severe bulbar signs (n = 1). Progressive myoclonic epilepsy was observed in two juvenile-onset cases before 20-year. A large CAG trinucleotide length was observed in the two juvenile-onset cases and genetic anticipation was observed in all cases. Neuroimaging studies disclosed cerebellar atrophy (n = 6), as well as brainstem and cerebellar atrophy (n = 2) and leukoencephalopathy (n = 1).ConclusionThe patients described herein reinforce that clinical features of DRPLA are highly influenced by age of onset, genetic anticipation and CAG repetition lengths. There is a large complex spectrum of neurological features associated with DRPLA, varying from pure cerebellar ataxia to dementia associated with other movement disorders (myoclonus, choreoathetosis). DRPLA is an unusual cause of cerebellar ataxia and neurodegeneration in Brazilian patients.     

Clinical features and ATTCT repeat expansion in spinocerebellar ataxia type 10

BACKGROUND: Spinocerebellar ataxia type 10, an autosomal dominant disease characterized by ataxia and seizures, is caused by a large expansion of an unstable ATTCT pentanucleotide repeat. OBJECTIVES: To characterize the phenotypic expression of spinocerebellar ataxia type 10 and to examine the genotype-phenotype correlations in 2 large families. DESIGN: Clinical characterization and genotype-phenotype correlation. SETTING: Studies at 2 medical schools with private practice referral. PATIENTS: Twenty-two affected individuals from 2 large Mexican American pedigrees. RESULTS: Of the 22 individuals, ataxia was the initial symptom in 21; seizure disorders developed in 11, mostly within several years following the onset of ataxia. The seizure frequency was different in the 2 families: 3 (25%) of 12 had seizures in family 1, and 8 (80%) of 10 had seizures in family 2 (P =.01). A brain magnetic resonance imaging or computed tomographic scan showed cerebellar atrophy in all patients examined. An electroencephalogram demonstrated epileptiform discharges in 4 of 8 patients studied. Although anticipation was apparent in both families, only family 1 showed a strong inverse correlation between age of onset and repeat number (r(2) = 0.79, P =.001). In family 1, 8 transmissions, of which 7 were paternal, resulted in an average gain of 1940 repeats. In contrast, despite anticipation, 2 affected male subjects transmitted their expanded alleles to 8 progenies, with an average loss of 755 repeats, in family 2. CONCLUSIONS: Seizure is an integral part of the spinocerebellar ataxia type 10 phenotype, with documented morbidity and mortality. Family-dependent factors may alter the frequency of the seizure phenotype and the pattern of intergenerational repeat size changes, making the genotype-phenotype correlation complex.     

Spastic paraplegia, ataxia, mental retardation (SPAR): a novel genetic disorder

OBJECTIVE: To describe a kindred with a dominantly inherited neurologic disorder manifested either as uncomplicated spastic paraplegia or ataxia, spastic paraplegia, and mental retardation. METHODS: Neurologic examinations and molecular genetic analysis (exclusion of known SCA and HSP genes and loci; and trinucleotide repeat expansion detection [RED]) were performed in six affected and four unaffected subjects in this family. MRI, electromyography (EMG), and nerve conduction studies were performed in three affected subjects. RESULTS: The phenotype of this dominantly inherited syndrome varied in succeeding generations. Pure spastic paraplegia was present in the earliest generation; subsequent generations had ataxia and mental retardation. MRI showed marked atrophy of the spinal cord in all patients and cerebellar atrophy in those with ataxia. Laboratory analysis showed that the disorder was not caused by mutations in genes that cause SCA-1, SCA-2, SCA-3, SCA-6, SCA-7, SCA-8, and SCA-12; not linked to other known loci for autosomal dominant ataxia (SCA-4, SCA-5, SCA-10, SCA-11, SCA-13, SCA-14, and SCA-16); and not linked to known loci for autosomal dominant hereditary spastic paraplegia (HSP) (SPG-3, SPG-4, SPG-6, SPG-8, SPG-9, SPG-10, SPG-12, and SPG-13) or autosomal recessive HSP SPG-7. Analysis of intergenerational differences in age at onset of symptoms suggests genetic anticipation. Using RED, the authors did not detect expanded CAG, CCT, TGG, or CGT repeats that segregate with the disease. CONCLUSIONS: The authors describe an unusual, dominantly inherited neurologic disorder in which the phenotype (pure spastic paraplegia or spastic ataxia with variable mental retardation) differed in subsequent generations. The molecular explanation for apparent genetic anticipation does not appear to involve trinucleotide repeat expansion.     

Clinical and genetic analysis of four Mexican families with spinocerebellar ataxia type 10

Spinocerebellar ataxia type 10 (SCA10) is an autosomal dominant disorder caused by expansion of an unstable ATTCT repeat. SCA10 has been described as a pure cerebellar syndrome accompanied by seizures and has been recognized only in families of Mexican origin. We describe clinical and molecular findings of 18 patients in four Mexican families with SCA10. Affected individuals had an average age at onset of 26.7 years (range 14-44 years) and ATTCT repeats ranging from 920 to 4,140 repeats. We could not detect significant anticipation or correlation between repeat size and age at onset, probably due to the small sample size. In addition to pure cerebellar ataxia and seizures, patients often showed soft pyramidal signs, ocular dyskinesia, cognitive impairment, and/or behavioral disturbances. Brain magnetic resonance imaging showed predominant cerebellar atrophy, and nerve conduction studies indicated polyneuropathy in 66% of patients. One family showed hepatic, cardiac, and hematological abnormalities in affected members. These findings suggest that a wide range of tissues may be affected in SCA10, including those outside of the cerebellum and cerebral cortex.     

Molecular and clinical study of spinocerebellar ataxia type 7 in Chinese kindreds

OBJECTIVE: To investigate the clinical and molecular characteristics of spinocerebellar ataxia type 7 (SCA7) in Chinese kindreds. BACKGROUND: Spinocerebellar ataxia type 7 is caused by the expansion of an unstable CAG repeat in the first exon of the SCA7 gene. METHODS: Clinical and related examinations were performed in all affected or at-risk individuals from 4 Chinese families presenting with autosomal dominant cerebellar ataxia and decreased visual acuity. The size of the (CAG)(n) array of the SCA7 gene was detected by polymerase chain reaction, polyacrylamide gel electrophoresis, and related techniques in the 4 families and 67 healthy controls. The relationship between expanded repeat number and age of onset was statistically analyzed. RESULTS: The SCA7 mutation was identified in 2 families. Clinical study revealed that great variation occurred in the age of onset, initial symptoms, and associated signs. Meanwhile, the analysis of 11 parent-child couples demonstrated the existence of marked anticipation. Some distinct retinal changes were noted in 2 affected patients. All SCA7 patients in our series exhibited expanded CAG repeats, ranging from 44 to 85 repeats, with a strong negative correlation between repeat size and age of onset. Repeat lengths of expanded alleles showed somatic mosaicism in leukocyte DNA. There were some subtle clinical differences between the SCA7-positive and -negative cases. CONCLUSIONS: Clinical variation occurred not only among the SCA7 families but also within the same kindred. Meiotic and mitotic instability of the CAG repeat in the SCA7 gene were demonstrated, and intergenerational instability of the array was associated with the clinical phenomenon of anticipation. Arch Neurol. 2000;57:1513-1518     

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.