Translated mutation in the Nurr1 gene as a cause for Parkinson's disease.

Multiple genes have been now identified as causing Parkinson's disease (PD). In 2003, two mutations were identified in exon 1 of the Nurr1 gene in 10 of 107 individuals with familial PD. To date, investigators have only focused on screening for these known mutations of the Nurr1 gene. All individuals were recruited from two Parkinson's disease clinics in Canada. Following PCR amplification of each exon of the Nurr1 gene, samples underwent denaturing high-performance liquid chromatography (DHPLC) analysis. Ten individuals also underwent direct sequencing as well as any samples where variants were identified. The Nurr1 gene was evaluated for 202 PD individuals, 37% of whom had at least one relative with PD and 100 control non-PD individuals. Using DHPLC and direct sequencing, we did not detect any sequence variants in exon 1. Variants in amplicon 6 were seen and direct sequencing confirmed a known NI6P polymorphism in intron 6. Novel polymorphisms were also identified in exon 3 and intron 5. A novel mutation was identified in exon 3 in one nonfamilial PD individual. This heterozygous C-to-G transversion resulted in a serine-to-cysteine substitution and was not identified in any of the other 602 chromosomes screened. Mutations in the Nurr1 gene in our large cohort of familial and sporadic PD individuals are rare. The novel mutation in exon 3 is predicted to affect phosphorylation and functional studies to assess this are underway. This is the first coding mutation identified in the Nurr1 gene for Parkinson's disease.     

R1514Q substitution in Lrrk2 is not a pathogenic Parkinson's disease mutation.

Mutations in LRRK2 were first reported as causing Parkinson's disease (PD) in late 2004. Since then, approximately a dozen LRRK2 substitutions have been identified that are believed to be pathogenic mutations. The substitution of adenine for guanine at nucleotide 4541 (4541G>A) in LRRK2 was recently reported. This substitution resulted in the replacement of an arginine at position 1514 with a glutamine (R1514Q). Although this substitution was not found in a large cohort of controls, its pathogenicity could not be verified. We have now genotyped the R1514Q substitution in a sample of 954 PD patients from 429 multiplex PD families. This substitution was identified in 1.8% of the PD patients; however, the majority of the PD sibships segregating this substitution were discordant for this putative mutation. In addition, the R1514Q substitution was detected in 1.4% of neurologically evaluated, control individuals. These data suggest that the R1514Q variant is not a pathogenic LRRK2 mutation. We believe it is imperative that the causative nature of any newly identified genetic variant be determined before it is included in any panel for diagnostic testing.     

Mutation of the Parkin gene in a Persian family: clinical progression over a 40-year period.

We report on an Israeli family originating from Iran in which 4 of 7 brothers born from a consanguineous marriage had juvenile Parkinsonism. Linkage analysis of markers covering the autosomal recessive juvenile Parkinsonism (AR-JP, PARK2, Parkin gene, OMIM #602544) gene resulted in a maximal logarithm of odds score of 2.18. A homozygous deletion that expanded from exon 4 to exon 6 was identified in all the patients. Significant clinical heterogeneity was present between siblings.     

帕金森病患者Parkin基因的研究

目的 研究Parkin基因缺失在早发性和晚发性帕金森病（PD）患者中的分布情况，探讨其在不同亚型PD发病机制中的可能作用。方法 对63例PD患者分为早发性PD组和晚发性PD组。以提取的基因组DNA为模板，扩增Parkin基因2～5号外显子，然后行琼脂糖电泳，观察外显子的缺失分布。结果 63例PD患者中发现外显子2、4缺失各1例，外显子3缺失2例，这些缺失均出现于早发性PD组。结论 Parkin基因外显子缺失可能是我国早发性PD患者的致病基因之一。     

Lack of G2019S LRRK2 mutation in a cohort of Taiwanese with sporadic Parkinson's disease.

Mutations in the leucine-rich repeat kinase 2 (LRRK2) gene have been shown to cause autosomal dominant and sporadic Parkinson's disease (PD). We report here the frequency of a common heterozygous mutation, 2877510G>A, which produces a glycine-to-serine amino acid substitution at codon 2019 in idiopathic Taiwanese PD. The extreme rarity of the G2019S mutation in our population suggests the occurrence of this mutation resulted from a common European founder.     

Analysis of 14 LRRK2 mutations in Parkinson's plus syndromes and late-onset Parkinson's disease.

The pleomorphic pathology of postmortem LRRK2-positive patients and the frequent association with late-onset Parkinson's disease (LOPD) symptoms suggest that LRRK2 mutations may play a role in Parkinson's Plus disorders and LOPD. Published studies primarily focus on the common G2019S mutation. Analysis of a spectrum of LRRK2 mutations in Parkinson's Plus disorders has yet to be reported. We investigated 14 leucine-rich repeat kinase 2 (LRRK2) mutations in a cohort of Parkinson's Plus disorders and LOPD. A total of 458 patients with progressive supranuclear palsy (PSP), multiple system atrophy (MSA), corticobasal ganglionic degeneration (CBGD), atypical Parkinsonism (AP), and LOPD were screened for 14 mutations that span exons 19 to 41 of the LRRK2 gene. Among the LOPD cases, 1 patient was found to harbor the R1441C mutation. He presented with typical features of PD at age of 58 years old and responded well to levodopa. We did not detect any of the 14 mutations in PSP, MSA, CBGD, and AP patients. We highlight the first case of LRRK2 R1441C mutation in late onset sporadic PD of non-European ancestry. Furthermore, extensive mutational screen found LRRK2 mutations to be rare among patients who presented with PSP, MSA, CBGD, and AP.     

G2019S LRRK2 mutation in familial and sporadic Parkinson's disease in Russia.

Among mutations associated with autosomal dominant and sporadic Parkinson's disease (PD) the G2019S substitution in the leucine-rich repeat kinase 2 (LRRK2) gene is the most frequently identified. To estimate its frequency in Russia, we analyzed 208 patients with PD from the Northwestern region of Russia. Of these, 51 patients were probands from families with PD compatible with autosomal dominant inheritance. The control group represented 161 subjects without neurological disorders settled in the same region. The frequency of the G2019S mutation was greater in familial PD (2 [3.9%] of 51) than in sporadic PD (1 [0.6%] of 157). In addition, this mutation was found in the proband's father, who also had PD, in 1 PD family, and in 1 carrier without signs of PD at age 40 in another PD family. All carriers were heterozygous for the G2019S mutation and reported the Ashkenazi Jewish origin. The mutation was not found in the control group.     

The Lille apathy rating scale (LARS), a new instrument for detecting and quantifying apathy: validation in Parkinson's disease

BACKGROUND: Apathy is usually defined as reduced interest and participation in various activities. It is a frequent consequence of neurological and psychiatric disorders. Although various scoring methods have been proposed, there is a lack of validated, standardised instruments for detecting apathy and assessing its severity. OBJECTIVE: To develop an apathy rating scale using a structured standardised interview capable of distinguishing between the condition's various features. METHODS: The Lille Apathy Rating Scale (LARS) is based on a structured interview. It includes 33 items, divided into nine domains. Responses are scored on a dichotomous scale. The participants used to validate the scale consisted of 159 patients with probable Parkinson's disease and 58 healthy control subjects. The Marin Apathy Scale, the Montgomery and Asberg Depression Rating Scale, and the Mattis Dementia Rating Scale were also administered. RESULTS: Principal component analysis showed that the LARS probed a single construct which forms the root of an oblique factor structure reflecting four dimensions: intellectual curiosity, self awareness, emotion, and action initiation. The main psychometric properties of the LARS (internal consistency, inter-rater and test-retest reliability) were satisfactory. Concurrent validity was evaluated by reference to the Marin scale and to judgements provided by expert clinicians. CONCLUSIONS: Standard validity indices showed that the LARS is sensitive and capable of distinguishing between apathy and depression. As a screening tool, the scale is able to support dichotomous judgements accurately and, when greater measurement sensitivity is required, also determine the severity of apathy within a four category classification.     

The contribution of Parkin,PINK1 and DJ‐1 genes to selective neuronal degeneration in Parkinson's disease

Parkinson's disease (PD) is characterised by selective and severe degeneration of the substantia nigra pars compacta and the locus coeruleus (LC), which underlies the most prominent symptoms. Although α‐synuclein accumulation has long been established to play a causal role in the disease, it alone cannot explain the selective degenerative pattern. Recent evidence shows that the selective vulnerability could arise due to the large presence of cytosolic catecholamines and Ca²⁺ ions in the substantia nigra pars compacta and LC specifically that can be aberrantly affected by α‐synuclein accumulation. Moreover, each has its own toxic potential, and disturbance of one can exacerbate the toxic effects of the others. This presents a mechanism unique to these areas that can lead to a vicious degenerative cycle. Interestingly, in familial variants of PD, the exact same brain areas are affected, implying the underlying process is likely the same. However, the exact disease mechanisms of many of these genetic variants remain unclear. Here, we review the effects of the PD‐related genes Parkin, PINK1 and DJ‐1. We establish that these mutant varieties can set in motion the same degenerative process involving α‐synuclein, cytosolic catecholamines and Ca²⁺. Additionally, we show indications that model organisms might not accurately represent all components of this central mechanism, explaining why Parkin, PINK1 and DJ‐1 model organisms often lack a convincing PD‐like phenotype.     

Evaluation of Parkinson's disease in entrants on the Nebraska State Parkinson's Disease Registry.

We examined a sample of individuals in the Nebraska State Parkinson's Disease Registry (NSPDR) to determine what proportion meets standard criteria for Parkinson's disease (PD). The NSPDR was established in 1996 in an effort to understand the high prevalence of PD in Nebraska. Only minimal demographic data are included for each entrant. Subjects enter the NSPDR by means of diagnosing physicians, pharmacists dispensing anti-PD medications and the patients themselves. A series of 356 registrants diagnosed between 1997 and 2001 were contacted and invited to participate in a case-control study. Medical records were reviewed by a single abstractor in a standard manner. When patients consented, history was filled in by interview. A subset of patients were examined by a movement disorders specialist, who assigned all patients a probability of PD. Where sufficient information was available, 78% of registrants were confirmed to have PD (i.e., percent probability > 50%), including 83% of the patients previously diagnosed by a neurologist. Tremor was an initial symptom in 72% of confirmed versus 39% of excluded cases, and resting tremor was present in 86% of those that were confirmed. The most frequent reasons for exclusion were drug-induced Parkinsonism, multiple systems atrophy, vascular disease, and essential tremor. Use of the NSPDR for epidemiologic study requires careful review of the data set before assignment of cases. When histories are compiled in a standardized, comprehensive manner, the necessity for actual patient examinations can be minimized.     

Neuropathology of Parkinson's disease associated with the LRRK2 Ile1371Val mutation.

Leucine-Rich Repeat Kinase 2 (LRRK2) gene mutations are the most common known cause of Parkinson's disease (PD), but neuropathological studies are available on very few patients with LRRK2 mutation. The reported findings range from Lewy body-positive pathology to different pathologies, including nigral degeneration without distinctive features, neuronal loss with only ubiquitin-positive inclusions, and tau-positive-only pathology. Here we report the first neuropathological study in an Italian PD case carrying a different LRRK2 mutation, Ile1371Val, and showing typical ubiquitin- and alpha-synuclein-positive Lewy body pathology. These findings support the concept that the neurodegeneration associated with LRRK2 mutations might be clinically and pathologically indistinguishable from typical PD.     

广西地区一个早发性帕金森病家族Parkin基因的研究

目的：研究Parkin基因1～12号外显子缺失突变、点突变与一个早发性帕金森病（EOPD）家族的关系。方法：采用聚合酶链反应（PCR）扩增2例临床确诊为EOPD患者及其亲属的Parkin基因1～12号外显子;用琼脂糖凝胶电泳和单链构象多态性分析检测Parkin基因1～12号外显子缺失突变和点突变;将1例患者Parkin基因的1～12号外显子进行测序,对发现有异常的外显子,用斑点杂交、放射显影定性方法检测其亲属相应的外显子。结果：所有研究对象均未检测到Parkin基因1～12号外显子缺失突变。结论：在2例患者及2名无临床症状亲属新发现7号外显子同义杂合点突变C869T,但此突变没有引起蛋白质序列改变（Arg256Arg）。     

Parkin variants in North American Parkinson's disease: cases and controls.

We report on an evaluation of coding variants within the parkin gene to assess their frequency in a North American clinical series of 313 Parkinson's disease (PD) cases and 192 unrelated controls. We hypothesized that the carrier frequency of parkin coding mutations, exon deletions, or duplications may be greater in PD cases. However, point mutations and exonic deletions/duplications, reported previously as pathogenic in homozygous or compound heterozygous individuals, occurred in both cases and controls with similar frequencies (3.8% in cases, 3.1% in controls). Furthermore, only stratified subanalyses detected any genetic association between the V380L common coding polymorphism and PD. We discuss the implication of parkin mutations for Parkinson's disease from this population perspective.     

Prevalence of Parkinson's disease and related disorders in the elderly population of greater Beijing, China.

A lower prevalence of Parkinson's disease (PD) has been reported for Chinese populations, but it is unclear whether this observation reflects a lower disease risk or is an artifact of case finding. We ascertained the prevalence of PD in elderly residents of an area that was a composite of 27 urban and rural communities of Greater Beijing, China. A team of university neurologists went door-to-door throughout the study area, examining 5,743 residents (at age 55 years or older) and made preliminary determinations of which residents had PD or other types of parkinsonism. Final determinations were made after follow-up and reevaluation of those persons who were either deemed to have parkinsonism or were suspected of having the condition (n = 144; median follow-up = 40 months). Based on stringent diagnostic criteria, 110 persons were identified to have parkinsonism, of whom 64 (58%) had PD. The prevalence of PD increased with advancing age and was about 1% overall and for each gender. In rural communities, 22 persons had PD, but 20 persons (91%) were first diagnosed for this condition by the study neurologists. The prevalence figures obtained in this study are similar to some of the highest prevalence figures reported in the West.     

Acupuncture therapy for the symptoms of Parkinson's disease.

Interest in alternative medical treatments, including acupuncture, is increasing. Alternative treatments must be subjected to the same objective standards as all medical treatments. A non-blinded pilot study of the safety, tolerability, and efficacy of acupuncture (ACUPX) for the symptoms of (PD) was performed. Twenty PD patients (mean age, 68 years; disease duration, 8.5 years; Hoehn and Yahr [H&Y] stage, 2.2; Unified Parkinson's Disease Rating Scale score [UPDRS], 38.7) each received acupuncture treatments by a licensed acupuncturist. All patients were treated with two acupuncture treatment sessions per week. The first seven patients received 10 treatments and the last 13 patients 16 treatments. Patients were evaluated before and after ACUPX with the Sickness Impact Profile (SIP); UPDRS; H & Y; Schwab and England (S & E); Beck Anxiety Inventory (BAI); Beck Depression Inventory (BDI); quantitative motor tests, including timed evaluations of arm pronation supination movements, finger dexterity, finger movements between two fixed measured points, and the stand-walk-sit test; and a patient questionnaire designed for the study. Following ACUPX, there were no significant changes in the UPDRS, H&Y, S&E, BAI, BDI, quantitative motor tests, total SIP or the two SIP Dimension scores. Analysis of the 12 SIP categories not corrected for multiple comparisons revealed a post-ACUPX improvement in the sleep and rest category only (P = 0.03). On the patient questionnaire, 85% of patients reported subjective improvement of individual symptoms including tremor, walking, handwriting, slowness, pain, sleep, depression, and anxiety. There were no adverse effects. ACUPX therapy is safe and well tolerated in PD patients. A range of PD and behavioral scales failed to show improvement following ACUPX other than sleep benefit, although patients reported other discrete symptomatic improvements. A broad battery of tests in PD patients suggested that ACUPX resulted in improvement of sleep and rest only. This finding needs to be verified using more in-depth and controlled evaluation of ACUPX for PD-related sleep disturbance.     

Presence of spinocerebellar ataxia type 2 gene mutation in a patient with apparently sporadic Parkinson's disease: clinical implications.

Among 242 patients with apparently sporadic Parkinson's disease, a 70-year-old man with a CAG repeat number of 37 in the SCA2 gene was identified. He has remained responsive to levodopa 14 years after onset and has had no overt signs suggesting cerebellar dysfunction. Although it is not possible to confirm if this patient has a de novo mutation of the SCA2 gene, this genetic defect seems to be contributing to his parkinsonian features and further supports the concept that apparently sporadic, late-onset, levodopa-responsive Parkinson's disease may have multiple causes.     

VPS35 mutation in Japanese patients with typical Parkinson's disease

Vacuolar protein sorting 35 (VPS35) was recently reported to be a pathogenic gene for late‐onset autosomal dominant Parkinson's disease (PD), using exome sequencing. To date, VPS35 mutations have been detected only in whites with PD. The aim of the present study was to determine the incidence and clinical features of Asian PD patients with VPS35 mutations. We screened 7 reported nonsynonymous missense variants of VPS35, including p.D620N, known as potentially disease‐associated variants of PD, in 300 Japanese index patients with autosomal dominant PD and 433 patients with sporadic PD (SPD) by direct sequencing or high‐resolution melting (HRM) analysis. In addition, we screened 579 controls for the p.D620N mutation by HRM analysis. The p.D620N mutation was detected in 3 patients with autosomal dominant PD (1.0%), in 1 patient with SPD (0.23%), and in no controls. None of the other reported variants of VPS35 were detected. Haplotype analysis suggested at least 3 independent founders for Japanese patients with p.D620N mutation. Patients with the VPS35 mutation showed typical tremor‐predominant PD. We report Asian PD patients with the VPS35 mutation. Although VPS35 mutations are uncommon in PD, the frequency of such mutation is relatively higher in Japanese than reported in other populations. In VPS35, p.D620N substitution may be a mutational hot spot across different ethnic populations. Based on the clinical features, VPS35 should be analyzed in patients with PD, especially autosomal dominant PD or tremor‐predominant PD. © 2012 Movement Disorder Society