Hereditary ataxias and paraplegias in Valle ďAosta, Italy: a study of prevalence and disability

Introduction - a study was conducted in the Valle ďAosta Region, Italy, (115270 inhabitants) to determine the prevalence of hereditary ataxias (HA) and hereditary spastic paraplegias (HSP), and the degree of disability they cause. Methods - we identified all patients with suspected HA or HSP referred from 1981 to 1991 to in- and out-patient departments, EEG, EMG, and CT-scan services, and centres for the handicapped. Harding's criteria were followed for diagnosis and classification. Results - at the prevalence day, 17 patients were alive, with a prevalence ratio of 14.8/100000 population. There were 2 cases of Friedreich's ataxia (FA), 1 of early onset cerebellar ataxia with retained tendon reflexes (EOCA), 1 of autosomal dominant cerebellar ataxia (ADCA), 8 of sporadic idiopathic late onset cerebellar ataxias, and 5 of HSP. Conclusions - epidemiological studies on HA and HSP show higly variable prevalence ratios, which could be due in part to the inclusion of sporadic cases. FA, EOCA and ADCA have similar prevalence ratios in most studies.     

The hereditary spastic paraplegias

The hereditary spastic paraplegias are a complex group of neurodegenerative conditions which are characterised by slowly progressive lower limb spasticity. This article describes the main clinical features of pure and complicated hereditary spastic paraplegias and summarises recent advances in our understanding of the molecular genetics of these conditions. Received: 2 June 1999 Accepted: 7 August 1999     

EFNS guidelines on the molecular diagnosis of ataxias and spastic paraplegias

Background and purpose: These EFNS guidelines on the molecular diagnosis of neurogenetic disorders are designed to provide practical help for the general neurologist to make appropriate use of molecular genetics in diagnosing neurogenetic disorders. Methods: Literature searches were performed before expert members of the task force wrote proposals, which were discussed in detail until final consensus had been reached among all task force members. Results and conclusion: This paper provides updated guidelines for molecular diagnosis of two particularly complex groups of disorders, the ataxias and spastic paraplegias. Possibilities and limitations of molecular genetic diagnosis of these disorders are evaluated and recommendations are provided.     

Spinocerebellar ataxias in Asia: Prevalence,phenotypes and management

This paper reviews and summarizes three main aspects of spinocerebellar ataxias (SCA) in the Asian population. First, epidemiological studies were comprehensively reviewed. Overall, the most common subtypes include SCA1, SCA2, SCA3, and SCA6, but there are large differences in the relative prevalence of these and other SCA subtypes between Asian countries. Some subtypes such as SCA12 and SCA31 are rather specific to certain Asian populations. Second, we summarized distinctive phenotypic manifestations of SCA patients of Asian origin, for example a frequent co-occurrence of parkinsonism in some SCA subtypes. Lastly, we have conducted an exploratory survey study to map SCA-specific expertise, resources, and management in various Asian countries. This showed large differences in accessibility, genetic testing facilities, and treatment options between lower and higher income Asian countries.Currently, many Asian SCA patients remain without a final genetic diagnosis. Lack of prevalence data on SCA, lack of patient registries, and insufficient access to genetic testing facilities hamper a wider understanding of these diseases in several (particularly lower income) Asian countries.     

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。     

Transcranial magnetic stimulation in hereditary ataxias: Diagnostic utility,pathophysiological insight and treatment

Transcranial magnetic stimulation (TMS) is a valuable technique to assess and modulate human brain function in normal and pathological conditions. This critical review surveys the contributions of TMS to the diagnosis, insight into pathophysiology and treatment of genetically confirmed hereditary ataxias, a heterogeneous group of neurodegenerative disorders that can affect motor cortex and the corticospinal tract. Most studies were conducted on small sample sizes and focused on diagnostic approaches. The available data demonstrate early involvement of the corticospinal tract and motor cortex circuitry, and support the possible efficacy of cerebellar repetitive TMS (rTMS) as therapeutic approach. Further TMS-based studies are warranted, to establish biomarkers for early diagnosis and disease monitoring, explore the involvement of the cerebello-dentato-thalamo-cortical projection, study the effects of rTMS-induced plasticity, and utilize rTMS for treatment.     

Gait analysis of sporadic and hereditary spastic paraplegia

Abstract.Objectives: Sporadic (SSP) and hereditary spastic paraplegias (HSP) are clinically and genetically heterogeneous disorders, which are characterised by a slowly progressive spastic paraparesis. Initial symptoms and the rate of progression are variable even among members of the same family. Spastic paraparesis is the major and most disabling clinical symptom and was assessed with gait analysis using a three-dimensional infrared movement analysis system.Methods and results: 22 patients with clinically and/or genetically confirmed SSP/HSP were compared with age-matched control subjects. Significantly lower values were found for gait velocity, stride length, step height and the range of motion of the knee-angle. The gait pattern is characterised by a severe spasticity of both legs with only mild paresis. The balance-related gait parameters show a broad-based gait without inwardly rotated feet. No correlation was found between disease duration and the severity of the gait disorder and the central motor conduction time to the leg muscles and the abnormal gait parameters. The gait pattern did not differ between the 7 SSP cases and the 15 HSP cases.Conclusions: We conclude that three-dimensional gait analysis can uncover specific features of such rare gait disorders, and may be used as an objective tool to quantify the impairment of gait parameters in patients with SSP/HSP and thus can be used to monitor disease progression and the effect of therapeutic interventions.     

遗传性痉挛性截瘫的神经外科治疗

目的 ;探讨遗传性痉挛性截瘫的神经外科治疗方法及其疗效。方法对17例遗传性痉挛性截瘫患者施行周围神经缩窄术,其中单纯周围神经缩窄术12例,周围神经缩窄+矫形术5例。采用改良Asworth分级评定患者的痉挛程度,采用简化Fugl-Meyer量表评估患者下肢运动功能的改善。结果随访8~15个月,平均12个月。术后近期痉挛缓解率为98.5%,随访期间为92.7%。术后近期下肢运动改善率为86.5%,随访期间为90.8%。2例(11.8%)患者下肢出现短暂的感觉障碍,随访期间均消失。1例(5.9%)严重痉挛患者术后伴有肌力减低。2例(11.8%)患者随访期间痉挛复发。结论遗传性痉挛性截瘫患者适时适当的进行外科手术治疗能够较好地缓解痉挛,改善下肢运动功能,延缓病程进展。     

Clinical and genetic update of hereditary spastic paraparesis

Hereditary spastic paraparesis is a group of inherited neurological diseases characterized by underlying wide genetic heterogeneity. It should be suspected if there is a positive familial history, a common genetic alteration (i.e. SPG4, the most overall frequent form), or association with other signs, such as cerebellar ataxia (i.e. SPG7), early cognitive impairment or even cognitive deficit (i.e. SPG11), or peripheral neuropathy (i.e. SACS). The natural history is known for certain genetic subgroups, with genotype-phenotype correlations partially explaining childhood or late onset. However, the search for genetic modifying factors, in addition to the causal pathogenic variant or environmental influencers, is still needed. Novel approaches to provide etiological treatment are in the pipeline for SPG11. Symptomatic treatments are available but would benefit from randomized controlled trials.     

Spastin mutation screening in Chinese patients with pure hereditary spastic paraplegia

BackgroundHereditary spastic paraplegia (HSP) is a clinically and genetically heterogeneous group of neurodegenerative diseases. Mutations in the spastin (SPAST) gene are the most common cause of pure HSP. However, few data are available regarding the clinical and genetic spectrum of HSP among Chinese patients.MethodsClinical data were collected at diagnosis and follow-up of 42 Chinese patients with pure HSP. All seventeen exons of the SPAST gene were directly sequenced. Additionally, we used a multiplex ligation dependent probe amplification (MLPA) assay targeting the SPAST gene to evaluate large exon deletion or insertion mutations in patients without SPAST point mutations.ResultsThe age of disease onset of our patients was 19.6 ± 14.4 years. Six novel variations were found, including three missense mutations (p. L363P, p. D441V, and p. S595R), one insertion (c.1511dupT (p. Y505Ifs*7)), and two larger deletions (exons 5–17 and exons 10–17). Four previously reported mutations, including p. S399L, c.1215_c.1219delTATAA (p. N405Kfs*36), exon 1 deletion, and exon 16 deletion, were detected. The SPAST mutation rate was 40% (4/10) in Chinese familial patients and 33.33% (7/21) in Chinese sporadic pure HSP patients. The frequency of large deletions was high in both AD-HSP (20%, 2/10) and sporadic HSP (14.28%, 3/21).ConclusionSPAST mutations are common in Chinese patients with pure HSP. Large exon deletions are an important cause of AD-HSP and sporadic pure HSP in Chinese patients. Large fragment tests should be performed to explore large SPAST mutations in familial and sporadic HSP patients without SPAST point mutations.     

遗传性痉挛性截瘫伴薄型胼胝体的临床特征

目的 探讨遗传性痉挛性截瘫伴薄型胼胝体（HSP-TCC）的临床特征。方法 对4例HSP-TCC患者的临床资料进行回顾性分析。结果 4例患者均于青少年起病，表现为智能低下，痉挛步态，双下肢痉挛，无力，腱反射亢进，病理征阳性，无感觉障碍，2例有共济失调及大小便障碍；1例有双上肢痉挛及肌肉萎缩，头颅MRI显示胼胝体变薄。结论 HSP-TCC的主要临床特征为青少年起病的痉挛性截瘫，智能低下，头颅MRI显示胼胝体变薄。     

Prevalence and incidence of Multiple Sclerosis in Campobasso (Molise region chieftown,southern Italy)

Objective

Multiple Sclerosis in southern Italy was not epidemiologically studied until 2006 in Salerno (Campania region), with data based on the registry of district MS centers established since 1996 by Italian Ministry of Health. This paper reports data about Molise region by the same metodology as Campanian study.

Patients and methods

The registry of MS center was searched for the city of Campobasso, chief town of Molise region. Population screened: 51,633 units. ISTAT 2005 data were used for comparison and age standardization. Prevalence day: September 30, 2009; incidence was calculated by cumulative rates 1996–2000 and 2001–2005.

Results

47 patients were collected, 17 males, 30 females, age 44.10 (9–74, SD 14.38); female/male ratio = 1.76/1; age onset 34.61 (4–61, SD 12.40); mean disease duration 9.48 years (0–24; SD 4.28). Males prevalence: 68.62/100,000; females: 111.68/100,000. Total prevalence: 91.02/100,000; standardized: 90.91/100,000. Incidence rates: 1996–2000: 10.84/100,000; 2001–2005: 4.26/100,000.

Conclusions

Prevalence is coherent with previous Campanian data, and with last epidemiologic papers on middle Italy, confirming also the validity of MS district centers registries. A possible underestimation of data, for some patients could still migrate to northern centers, could contribute to the differences in incidence. Nevertheless, prevalence data confirm southern Italy as high risk area for MS, and stands against a latitude gradient in this country.     

遗传性痉挛性截瘫一家系(SPG4)的临床与遗传学特点

目的 探讨遗传性痉挛性截瘫(HSP)4型患者的临床特点和基因突变. 方法观察HSP4型患者1个家系4例患者的临床特点,抽取家系5个成员的外周血,选择与已知HSP致病基因位点在物理距离上紧密连锁的微卫星分子STR进行标记.连锁分析并构建其单体型后进行突变筛选.结果 基因分型结果显示了D2S2351与D2S2255与致病基因不排除连锁.其他位点LOD值为负值排除连锁,因此初步定位于HSP致病基因(SPG)4,所对应的候选基因是spastin基因.突变筛查发现患者spastin基因第8外显子1168位置碱基A/G杂合突变.结论该HSP家系患者具有典型临床表现,为spastin基因第8外显子1168核苷酸的位置上A/G杂合突变所致.     

孪生子患单纯型遗传性痉挛性截瘫的临床与卵型鉴定

目的研究孪生子患单纯型遗传性痉挛性截瘫（HSP）的临床特征与卵型鉴定。方法对一对患单纯型HSP孪生兄弟的临床特点和症状进行分析并跟踪随访，同时作孪生子卵型鉴定。结果（1）孪生子均缓慢起病，步态不稳，下肢笨拙，上下楼困难，逐渐发展为双下肢痉挛性不完全性截瘫；（2）下肢肌张力增高，肌力Ⅳ级，腱反射亢进，髌、踝阵挛阳性，Babinski征阳性，屈性病理反射阳性；（3）16个STR位点的等位基因均相同，提示为同卵双生。结论孪生子同患单纯型HSP的临床特点与一般HSP无异，作16个STR位点的PCR可快速、准确地鉴定孪生子的卵型。     

Intragenic modifiers of hereditary spastic paraplegia due to spastin gene mutations

Hereditary spastic paraplegia (HSP) is a genetically heterogeneous neurodegenerative disease characterized by wide variability in phenotypic expression, both within and among families. The most-common cause of autosomal dominant HSP is mutation of the gene encoding spastin, a protein of uncertain function. We report the existence of intragenic polymorphisms of spastin that modify the HSP phenotype. One (S44L) is a previously described recessively acting allele and the second is a novel allele affecting the adjacent amino acid residue (P45Q). In 4 HSP families in which either L44 or Q45 segregates independently of a missense or splicing mutation in the AAA domain of spastin, L44 and Q45 are each associated with a striking decrease in age at onset in the presence of the AAA domain mutations. Using a bioinformatics approach, we found that the highly conserved S44 is predicted to be phosphorylated by a number of family members of the proline-directed serine/threonine cyclin-dependent kinases (Cdks). Cdk1 and Cdk5 showed no kinase activity toward synthetic spastin peptide in an in vitro kinase assay, suggesting that this serine residue may be phosphorylated by a different Cdk. Our identification of S44L and P45Q as modifiers of the HSP phenotype suggests a role for spastin phosphorylation by Cdks in the neurodegeneration of the most-common form of HSP.     

A novel NIPA1 mutation associated with a pure form of autosomal dominant hereditary spastic paraplegia

The hereditary spastic paraplegias (HSPs) are a clinically and genetically heterogeneous group of neurodegenerative disorders characterised by lower limb spasticity and weakness. Mutations in NIPA1 (Nonimprinted in Prader-Willi/Angelman syndrome 1) have recently been identified as a cause of autosomal dominant pure HSP, with one mutation described in two unrelated families. NIPA1 has no known function but is predicted to possess nine transmembrane domains and may function as a receptor or transporter. Here we present a large British pedigree in which linkage analysis conclusively demonstrates linkage to the NIPA1 locus (maximum multipoint LOD score 4.6). Subsequent mutation analysis identified a novel missense substitution in a highly conserved NIPA1 residue (G106R) which further confirms a causative link between NIPA1 mutation and autosomal dominant hereditary spastic paraplegia.     

Homozygosity mapping and next generation sequencing for the genetic diagnosis of hereditary ataxia and spastic paraplegia in consanguineous families

IntroductionGenetic inheritance plays key roles in patients with ataxia and/or spastic paraplegia in consanguineous families. This study aims to clarify the genetic spectrum of patients with autosomal recessive hereditary ataxia and spastic paraplegias (AR-HA/HSPs) in consanguineous families.MethodsA total of 36 AR-HA/HSPs consanguineous pedigrees from China were recruited into this study. Next generation sequencing (NGS), guided by homozygosity mapping (HM), was applied to identify the pathogenic variants in known genes or novel candidate genes.ResultsWe totally made molecular diagnosis in 47.2% (17/36) of AR-HA/HSPs families. Among them, 13 AR-HAs carried pathogenic variants in SETX (n = 4), SACS (n = 2), STUB1, HSD17B4, NEU1, ADCK3, TPP1, PLA2G6 and MTCL1, while four AR-HSPs carried pathogenic variants in SPG11, ZFYVE26, ATP13A2 and ABCD1. One homozygous nonsense mutation in MRPS27 was identified in an AR-HA family, which was potentially a novel candidate gene of AR-HA.ConclusionHM and NGS can serve as an efficient molecular diagnostic tool for AR-HA/HSPs in consanguineous families. Our findings provide a better understanding of genetic architecture of AR-HA/HSPs in consanguinity and broaden the clinical-genetic spectrum of the disease.     

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。     

贵州部分少数民族遗传性痉挛性截瘫Spastin基因突变研究

目的筛查及分析遗传性痉挛性截瘫(HSP)Spastin基因突变,了解贵州地区少数民族(彝族、布衣族、苗族)Spastin基因突变特点。方法应用PCR产物直接DNA测序法,对9例HSP患者(包括3个家系中7例现证者和2例散发患者)Spastin基因1-17号外显子进行突变筛查;被发现存在突变的外显子,其次行家系内其他成员相对应外显子的筛查。结果在9例HSP患者中发现家系3两例患者(Ⅴ24、Ⅴ25)的Spastin基因第4号外显子同一位点上发生错义突变c.847C>T,其他参与抽血的亲属均无该位点突变,推测该位点的突变为一多态。另外的突变位点均位于外显子序列前后的内含子区域。结论此次贵州地区部分少数民族spastin基因突变率低,与国内文献报道的汉族人群不同。