Toward identification of susceptibility genes for sporadic Parkinson's disease

To identify susceptibility genes for Parkinson's disease (PD) and to establish tailor-made medicine for PD, we studied 20 single nucleotide polymorphisms (SNPs) in 18 candidate genes for association with PD. We found that homozygosity for the V66M polymorphism of the BDNF gene occurs more frequently in PD patients than in unaffected controls and confirmed an association with the S18Y polymorphism of the UCHL1 gene. We further started microsatellite marker-based genome-wide association studies by using the pooled DNA method. We have finished checking approximately 6800 markers and found some significant associations (p=3.9 x 10(-6)) on chromosome 1 where other studies showed a linkage. Genes in linkage disequilibrium with these markers may be associated with pathogenesis of PD.     

Catechol-O-methyltransferase and monoamine oxidase B genes and susceptibility to sporadic Parkinson's disease in a Polish population

Recent reports have proved that genetic factors play a role in the pathogenesis of sporadic Parkinson's disease (PD). It has been suggested that polymorphisms in monoamine oxidase B (MAOB) and catechol-O-methyltransferase (COMT) might increase the risk of PD. A total of 210 Polish patients with sporadic PD and 152 healthy controls were studied. The MAOB and COMT polymorphisms were identified using the polymerase chain reaction-restriction fragment length polymorphism method. The MAOB allele and genotype frequencies in PD patients did not differ significantly from the controls. A statistically lower frequency of the COMTLL genotype in patients with parkinsonism was found. The combined haplotype of the MAOB G (G/G) and COMTHL genotype showed a fourfold increase (p < 0.05) in the risk of PD in female patients in this Polish population.     

Clinical and molecular genetics of primary dystonias

Primary dystonias are movement disorders with dystonia as a major symptom. They are frequently inherited as Mendelian traits. There are at least eight clinically distinct autosomal dominant and two X-linked recessive forms. In addition, pedigree analyses suggest the occurrence of an autosomal recessive variant. The clinical classification is increasingly being replaced by a genetic one. To date gene loci have been identified in at least six autosomal dominant forms, i.e., in idiopathic torsion dystonia (9q34), focal dystonia (18p), adult-onset idiopathic torsion dystonia of mixed type (8p21-q22), dopa-responsive dystonia (14q22.1-q22.2), and paroxysmal dystonic choreoathetosis (2q25-q33; 1p21-p13.3). Gene loci in the X-linked recessive forms have been assigned to Xq13.1 in the X-linked dystonia parkinsonism syndrome and to Xq22 in X-linked sensorineural deafness, dystonia, and mental retardation. The disease genes have been identified in two autosomal dominant forms and in one X-linked recessive form. Mutations in a gene coding for an ATP-binding protein were detected in idiopathic torsion dystonia (DYT1), and the GTP cyclohydrolase 1 gene is mutated in dopa-responsive dystonia (DYT5). In sensorineural deafness, dystonia, and mental retardation, mutations were found in the gene DDP coding for a polypeptide of unknown function. This article reviews the clinical and molecular genetics of primary dystonias, critically discusses present findings, and proposes referring to the known forms, most of which can be distinguished by genetic criteria, as dystonias 1–12. Received: January 12, 1998 / Accepted: January 19, 1998     

Botulinum toxins in the treatment of primary focal dystonias

Non-motor signs encountered in Parkinson's disease consist in a heterogeneous group of manifestations including hyposmia, pain, fatigue, sleep disorders, neuropsychic disorders. Functional imaging techniques provide an invaluable method to understand their pathophysiology, allowing us to study the abnormalities of brain metabolism or perfusion associated with these manifestations or the underlying dysfunction of different neurotransmission systems. The present paper covers the recent advances provided by functional imaging in this area.     

Characteristics of dystonic movements in primary and symptomatic dystonias

OBJECTIVE: To compare clinical characteristics of the involuntary movements in primary and symptomatic dystonias. PATIENTS AND METHODS: 132 consecutive patients with the diagnosis of primary dystonia and 51 consecutive patients with secondary dystonia caused by well defined structural lesion(s) of the central nervous system, with particular emphasis on the characteristics of involuntary movements. RESULTS: Eight variables with the highest risk contribution to either symptomatic or primary dystonias were identified: dystonic movement in secondary dystonia was much more frequently presented at rest, whereas the presence of dystonic tremor, chronic inflammatory process, or peripheral trauma located in the region that is later affected by dystonia, as well as the use of sensory tricks and development of spontaneous remissions, classified the affected patients more often in the category of those with primary dystonia. CONCLUSION: The study identified several clinical features that may be helpful in differentiating primary from secondary dystonia.     

EFNS原发性肌张力障碍诊断和治疗指南

目的 提供2006年版原发性肌张力障碍诊断和治疗指南的更新.背景 原发性肌张力障碍是主要发生于年轻人的临床表现多样的慢性致残性疾病.诊断 原发性肌张力障碍分为单纯肌张力障碍、肌张力障碍叠加综合征和阵发性肌张力障碍综合征.肌张力障碍的评价须使用经过验证的评定量表.遗传学检测应在临床诊断后实施.推荐DYT1检测用于发病年龄...     

EFNS guidelines on diagnosis and treatment of primary dystonias

Objectives: To provide a revised version of earlier guidelines published in 2006. Background: Primary dystonias are chronic and often disabling conditions with a widespread spectrum mainly in young people. Diagnosis: Primary dystonias are classified as pure dystonia, dystonia plus or paroxysmal dystonia syndromes. Assessment should be performed using a validated rating scale for dystonia. Genetic testing may be performed after establishing the clinical diagnosis. DYT1 testing is recommended for patients with primary dystonia with limb onset before age 30, and in those with an affected relative with early‐onset dystonia. DYT6 testing is recommended in early‐onset or familial cases with cranio‐cervical dystonia or after exclusion of DYT1. Individuals with early‐onset myoclonus should be tested for mutations in the DYT11 gene. If direct sequencing of the DYT11 gene is negative, additional gene dosage is required to improve the proportion of mutations detected. A levodopa trial is warranted in every patient with early‐onset primary dystonia without an alternative diagnosis. In patients with idiopathic dystonia, neurophysiological tests can help with describing the pathophysiological mechanisms underlying the disorder. Treatment: Botulinum toxin (BoNT) type A is the first‐line treatment for primary cranial (excluding oromandibular) or cervical dystonia; it is also effective on writing dystonia. BoNT/B is not inferior to BoNT/A in cervical dystonia. Pallidal deep brain stimulation (DBS) is considered a good option, particularly for primary generalized or cervical dystonia, after medication or BoNT have failed. DBS is less effective in secondary dystonia. This treatment requires a specialized expertise and a multidisciplinary team.     

DYT1 mutation in a cohort of Taiwanese primary dystonias

To investigate the DYT1 gene mutation in Chinese ethnic, we examined a series of 200 patients with primary dystonias (11 familial and 189 sporadic), 53 of their asymptomatic relatives, 97 patients with familial or early-onset parkinsonism, and 200 healthy subjects. The GAG deletion at codon 946 was only found in three sporadic dystonia patients and seven of their asymptomatic familial members. The frequency of GAG deletion was 1.5% in dystonia patients, and was 6.7% in early-onset dystonias (< or = 26 years). We conclude that DYT1 mutation is a minor cause of primary dystonias in a cohort of Taiwanese population.     

Coding polymorphisms in the parkin gene and susceptibility to Parkinson disease

BACKGROUND: Mutations in the parkin gene, an E3 protein-ubiquitin ligase, cause autosomal recessive early-onset Parkinson disease (PD). The role of polymorphisms in the parkin gene as risk factors for PD is still unclear, as the results in the literature are contradictory. PATIENTS: We compared the allele and genotype frequencies of the Ser167Asn, Arg366Trp, Val380Leu, and Asp394Asn polymorphisms in 194 patients with PD (92 familial and 102 sporadic) and 125 control subjects. RESULTS: Homozygous Val380 was significantly associated with sporadic PD (P =.008). There was also a trend toward an association of homozygous Asp394 with familial PD (P =.07). CONCLUSIONS: Some parkin polymorphisms appear to be risk factors for sporadic or familial PD. The functional effects of these coding polymorphisms need to be established, and further studies on parkin polymorphisms in PD should be undertaken.     

Validity and reliability of a rating scale for the primary torsion dystonias

For quantitative assessment of the primary torsion dystonias, a rating scale is proposed that has two sections--a Movement Scale, based on examination, and a Disability Scale, based on the patient's statements about seven activities of daily living. We assessed the validity of the Movement Scale by comparing scores with a ranking of patients according to dystonia severity and with ratings of the patients on the Disability Scale. In addition, we assessed the inter-and intra-rater reliability of the scale by comparing independent scorings of patients by four examiners and by comparing scorings by the same examiners performed at different times. We found that the Movement Scale was a valid and reliable indicator of the severity of primary torsion dystonia.     

ITGA4 polymorphisms and susceptibility to multiple sclerosis

In multiple sclerosis (MS), alpha(4)beta(1) integrin, also known as Very Late Antigen 4 (VLA4), facilitates migration of leukocytes across the blood brain barrier. Several studies suggest that expression of alpha(4) integrin may be increased in MS patients compared to controls, and down-regulation or antagonism of alpha(4) integrin may be associated with immunomodulatory treatment success. We analysed association of 13 single nucleotide polymorphisms (SNPs) in the gene encoding alpha(4) integrin (ITGA4) with susceptibility to MS in two distinct populations comprising cases and controls from the Basque Country in northern Spain (352 patients; 235 controls) and Nordic countries (1119 patients; 1235 controls). Carriage of the C allele of the ITGA4 promoter SNP rs1449263 was independently and weakly increased in MS patients from each population compared to respective controls (P = 0.037 in Basque; and P = 0.042 in Nordic cohorts), though these associations were lost upon application of permutation correction. Meta-analysis of rs1449263*C carriage revealed a Mantel-Haenszel common OR of 1.26 (95% CI 1.06-1.49; P = 0.0069). Though our data only modestly argue for a role of ITGA4 in determining susceptibility to MS, we suggest that further examination of this gene, particularly the promoter region, is warranted.     

Head trauma in primary cranial dystonias: a multicentre case-control study

Background

The relationship between prior trauma and primary adult‐onset dystonia is not well understood. Previous uncontrolled observations and exploratory case–control studies have yielded contradictory results.

Objective

To analyse the association between cranial dystonia and prior head trauma.

Methods

An ad hoc multicentre case–control study was performed using a semistructured interview to collect detailed information on the history of head trauma before disease onset in five Italian tertiary referral centres for movement disorders. The presence of a history of head trauma and of post‐traumatic sequelae (loss of consciousness, bone fractures, scalp/facial wounds) before disease onset was recorded from 177 patients with primary adult‐onset cranial dystonia and from 217 controls with primary hemifacial spasm matched by age strata and sex. Differences between groups were assessed by Mann–Whitney U test and Fisher''s exact test, and the relationship between prior head trauma and case/control status was analysed by multivariate logistic regression models.

Results

No association was found between vault/maxillofacial trauma and cranial dystonia. Most reported traumas occurred several years before disease onset. None of the main post‐traumatic sequelae altered the chance of developing cranial dystonia compared with patients with primary hemifacial spasm, nor did head trauma modify the age at onset of cranial dystonia.

Conclusions

These results do not support prior head trauma as a possible environmental factor modifying the risk of developing late‐onset cranial dystonia. The lack of association may have pathogenetic and medical–forensic implications.Cranial dystonia is an adult‐onset dystonia most commonly affecting the orbicularis oculi and oromandibular muscles.^1,2,3 Like other forms of primary adult‐onset dystonia, cranial dystonias are thought to be multifactorial in origin, with a possible contribution of both genetic and environmental factors.⁴Head trauma leading to structural lesions in the caudate, lentiform nuclei, thalami or midbrain is one of the possible causes of secondary dystonia.^5,6,7,8 A few uncontrolled studies have also suggested an association between cranial dystonia and head trauma in the absence of overt brain lesions.^9,10 Two possible pathogenic mechanisms have been proposed to explain the link between traumatic head injury and cranial dystonia.^9,10,11 The first is discrete brain damage in “sensitive” areas such as the basal ganglia. The second mechanism is that of a peripheral maxillofacial trauma inducing topographically related dystonia^12,13 through maladaptive plastic reorganisation of cortical and subcortical circuits.^{9,10,12,13,14} Two exploratory case–control studies nevertheless found no significant association with cranial dystonia.^15,16 Because these studies assessed a large number of variables owing to multiple testing, they were more liable to a higher risk of false positive results than ad hoc hypothesis‐testing studies. In addition, prior studies^15,16 only partly explored the relationship between dystonia and clinical features of the trauma (loss of consciousness, scalp or facial wounds, cranial or maxillofacial bone fractures), the topographical distribution of the trauma (vault or maxillofacial localisation) and the time elapsed from the trauma to the development of dystonia.To discuss these shortcomings and establish the relationship between previous head trauma and primary late‐onset cranial dystonia, we conducted an ad hoc multicentre case–control study, collecting detailed information on the history of head trauma antecedent to the onset of dystonia.     

Epidemiology of primary dystonias in Japan: comparison with Western countries.

We performed epidemiological studies of primary dystonia in the city of Kyoto. The prevalence was at least 10.1 per 100,000 persons, which was similar to that in Western countries. Facial dystonia was more common than other types, which contrasts with that reported in Europe. Age of onset for both genders was in agreement with that in other countries.     

Relative risk of spread of symptoms among the focal onset primary dystonias.

Adult-onset primary torsion dystonia (PTD) may spread to multiple body parts, but the relative risk of spread by site of onset of dystonia has not been well characterized. We retrospectively identified 602 patients with PTD out of 1,500 dystonia patients in our electronic database and extracted age at onset, site of onset, family history, and spread. Survival analyses were performed for groups based on site of onset, and hazard ratios compared relative risk of spread across groups. Patients with adult-onset blepharospasm were more likely to spread (31% past the head) than those with dystonia starting in the neck (9%), larynx (12%), or upper extremities (16%). Hazard ratios proved that the blepharospasm group had the greatest relative risk of spread. The rate of spread after onset varied significantly between the different groups. Most spread occurred in the first 1 to 2 years after onset of blepharospasm, whereas the risk of spread was relatively constant over time in cervical and laryngeal dystonia. Different sites of onset of PTD confer different risks of spread, important for clinical prognosis. Different risks of spread may provide clues about underlying pathogenesis of adult-onset primary dystonias.     

多巴胺D2,D3受体基因多态性与原发性震颤遗传易患性的相关研究

原发性震颤(ET)是一种其病因与多种因素相关、较常见的运动障碍性疾病,遗传因素是病因之一.研究证实ET与帕金森病(PD)是相关联的疾病,二者的震颤发生机制类似,均与中枢多巴胺能神经系统功能失调相关.为探讨多巴胺D2,D3受体基因多态与ET遗传易患的相关性,采用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)技术,首次检测80例无血缘相关的ET患者与100例正常对照DRD2基因Taq Ⅰ,DRD3基因Msp Ⅰ位点突变,比较ET与正常人之间的多态性频率的差异.DRD2基因Taq Ⅰ位点及DRD3基因Msp Ⅰ位点等位基因的基因型、基因频率分布在ET与正常对照无显著差异.DRD2基因Taq Ⅰ与DRD3基因Msp Ⅰ位点多态性可能与ET的遗传易患性无关.     

多巴胺D2，D3受体基因多态性与原发性震颤遗传易患性的相关研究

原发性震颤 (ET)是一种其病因与多种因素相关、较常见的运动障碍性疾病 ,遗传因素是病因之一。研究证实ET与帕金森病 (PD)是相关联的疾病 ,二者的震颤发生机制类似 ,均与中枢多巴胺能神经系统功能失调相关。为探讨多巴胺D2 ,D3受体基因多态与ET遗传易患的相关性 ,采用聚合酶链反应 限制性片段长度多态性(PCR RFLP)技术 ,首次检测 80例无血缘相关的ET患者与 10 0例正常对照DRD2基因TaqⅠ ,DRD3基因MspⅠ位点突变 ,比较ET与正常人之间的多态性频率的差异。DRD2基因TaqⅠ位点及DRD3基因MspⅠ位点等位基因的基因型、基因频率分布在ET与正常对照无显著差异。DRD2基因TaqⅠ与DRD3基因MspⅠ位点多态性可能与ET的遗传易患性无关。     

Lack of mutations in the epsilon-sarcoglycan gene in patients with different subtypes of primary dystonias.

Primary dystonias represent a clinically and genetically heterogeneous group of movement disorders. Mutations in the epsilon-sarcoglycan (SGCE) gene have been found recently to cause myoclonus-dystonia (MD). Considerable clinical variation of SGCE mutation carriers leads to the hypothesis that mutations in the SGCE gene might also be relevant for other subtypes of dystonias. To determine the contribution of mutations in the SGCE gene in patients with different subtypes of dystonias, we analyzed the coding sequence of the SGCE gene in a group of 296 patients with a clinical phenotype of primary dystonia and in 2 patients with a clinical phenotype of myoclonus-dystonia. Patients with mutations in the DYT1 gene were excluded. We could not detect a mutation in the SGCE gene in any of the 298 patients. Our results suggest that mutations in the SGCE gene cannot be held responsible for other subtypes of primary dystonia.