Multiple system atrophy (MSA) is an adult-onset, sporadic synucleinopathy characterized by parkinsonism, cerebellar ataxia, and dysautonomia. The genetic architecture of MSA is poorly understood, and ...treatments are limited to supportive measures. Here, we performed a comprehensive analysis of whole genome sequence data from 888 European-ancestry MSA cases and 7,128 controls to systematically investigate the genetic underpinnings of this understudied neurodegenerative disease. We identified four significantly associated risk loci using a genome-wide association study approach. Transcriptome-wide association analyses prioritized USP38-DT, KCTD7, and lnc-KCTD7-2 as novel susceptibility genes for MSA within these loci, and single-nucleus RNA sequence analysis found that the associated variants acted as cis-expression quantitative trait loci for multiple genes across neuronal and glial cell types. In conclusion, this study highlights the role of genetic determinants in the pathogenesis of MSA, and the publicly available data from this study represent a valuable resource for investigating synucleinopathies.
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•Generation of a foundational genomic resource in multiple system atrophy•GWAS identifies novel risk loci at GAB1, lnc-LRRC49-3, TENM2, and RABGEF1•Functional genomics implicates USP38-DT, KCTD7, and lnc-KCTD7-2 within these loci•Gene-burden analysis identifies nominal enrichment of rare missense mutations in KCTD7
Chia et al. comprehensively analyzed genome sequence data from patients with multiple system atrophy (MSA) and controls. The study identified four novel risk loci associated with MSA and prioritized significantly associated genes (USP38-DT, KCTD7, and lnc-KCTD7-2) within these loci. This initiative's data constitute a valuable resource for the research community.
There is little information on the late stages of parkinsonism.
We conducted a multicentre study in 692 patients with late stage parkinsonism in six European countries. Inclusion criteria were ...disease duration of ≥7 years and either Hoehn and Yahr stage ≥4 or Schwab and England score of 50 or less.
Average disease duration was 15.4 (SD 7.7) years and mean total UPDRS score was 82.7 (SD 22.4). Dementia according to MDS-criteria was present in 37% of patients. Mean levodopa equivalence dose was 874.1 (SD 591.1) mg/d. Eighty two percent of patients reported falls, related to freezing (16%) or unrelated to freezing (21% of patients) or occurring both related and unrelated to freezing (45%), and were frequent in 26%. Moderate-severe difficulties were reported for turning in bed by 51%, speech by 43%, swallowing by 16% and tremor by 11%. Off-periods occurred in 68% and were present at least 50% of the day in 13%, with morning dystonia occurring in 35%. Dyskinesias were reported by 45% but were moderate or severe only in 7%. Moderate-severe fatigue, constipation, urinary symptoms and nocturia, concentration and memory problems were encountered by more than half of participants. Hallucinations (44%) or delusions (25%) were present in 63% and were moderate-severe in 15%. The association with overall disability was strongest for severity of falls/postural instability, bradykinesia, cognitive score and speech impairment.
These data suggest that current treatment of late stage parkinsonism in the community remains insufficiently effective to alleviate disabling symptoms in many patients.
•The most common complications were falls, off-periods, speech and swallowing problems, and autonomic and psychiatric complications, fatigue and dementia.•Despite moderate doses of levodopa only 7% had moderate to severe dyskinesia.•Disability was predominantly influenced by motor severity, overall bradykinesia and axial features but also speech impairment.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Multiple system atrophy (MSA) is a neurodegenerative disorder characterized by a combination of autonomic failure plus cerebellar syndrome and/or parkinsonism. Dysphagia is a frequent and disabling ...symptom in MSA and its occurrence within 5 years of motor onset is an additional diagnostic feature. Dysphagia can lead to aspiration pneumonia, a recognized cause of death in MSA. Guidelines for diagnosis and management of dysphagia in MSA are lacking. An International Consensus Conference among experts with methodological support was convened in Bologna to reach consensus statements for the diagnosis, prognosis, and treatment of dysphagia in MSA. Abnormalities of the oral and pharyngeal phases of swallowing, esophageal dysfunction and aspiration occur in MSA and worsen as the disease progresses. According to the consensus, dysphagia should be investigated through available screening questionnaires and clinical and instrumental assessment (videofluoroscopic study or fiberoptic endoscopic evaluation of swallowing and manometry) at the time of MSA diagnosis and periodically thereafter. There is evidence that dysphagia is associated with poor survival in MSA, however effective treatments for dysphagia are lacking. Compensatory strategies like diet modification, swallowing maneuvers and head postures should be applied and botulinum toxin injection may be effective in specific conditions. Percutaneous endoscopic gastrostomy may be performed when there is a severe risk of malnutrition and pulmonary complications, but its impact on survival is undetermined. Several research gaps and unmet needs for research involving diagnosis, prognosis, and treatment were identified.
•Dysphagia is a frequent and disabling symptom in MSA.•Dysphagia can lead to aspiration pneumonia, a cause of death in MSA.•Consensus statements for diagnosis, prognosis, treatment of dysphagia are supplied.•Unmet needs for research on dysphagia in MSA are also identified.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
We performed a three-stage genome-wide association study (GWAS) to identify common Parkinson's disease (PD) risk variants in the European population. The initial genome-wide scan was conducted in a ...French sample of 1039 cases and 1984 controls, using almost 500 000 single nucleotide polymorphisms (SNPs). Two SNPs at SNCA were found to be associated with PD at the genome-wide significance level (P < 3 × 10(-8)). An additional set of promising and new association signals was identified and submitted for immediate replication in two independent case-control studies of subjects of European descent. We first carried out an in silico replication study using GWAS data from the WTCCC2 PD study sample (1705 cases, 5200 WTCCC controls). Nominally replicated SNPs were further genotyped in a third sample of 1527 cases and 1864 controls from France and Australia. We found converging evidence of association with PD on 12q24 (rs4964469, combined P = 2.4 × 10(-7)) and confirmed the association on 4p15/BST1 (rs4698412, combined P = 1.8 × 10(-6)), previously reported in Japanese data. The 12q24 locus includes RFX4, an isoform of which, named RFX4_v3, encodes brain-specific transcription factors that regulate many genes involved in brain morphogenesis and intracellular calcium homeostasis.
Abstract Despite active fundamental, translational and clinical research, no therapeutic intervention has yet shown convincing effects on disease progression in Parkinson's disease (PD) patients. ...Indeed, several disease-modification trials failed or proved to be inconclusive due to lack of consistency between clinical rating scales and putative surrogate markers of disease progression, or confounding symptomatic effects of the tested compound. Multiple system atrophy (MSA) is a rapidly progressing orphan disorder leading to severe motor disability within a few years. Together with PD and dementia with Lewy bodies (DLB), MSA belongs to the synucleinopathies, a group of neurodegenerative disorders characterized by the abnormal accumulation of alpha-synuclein. Crucial milestones have been reached for successfully conducting clinical intervention trials in a large number of patients with MSA. In this personal view, we will review evidence, and discuss why MSA could prove the most relevant clinical model for assessing treatments that target mechanisms operating in all synucleinopathies.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Chorea-acanthocytosis (ChAc) is a neuroacanthocytosis syndrome presenting with severe movement disorders poorly responsive to drug therapy. Case reports suggest that bilateral deep brain stimulation ...(DBS) of the ventro-postero-lateral internal globus pallidus (GPi) may benefit these patients. To explore this issue, the present multicentre (n=12) retrospective study collected the short and long term outcome of 15 patients who underwent DBS.
Data were collected in a standardized way 2-6 months preoperatively, 1-5 months (early) and 6 months or more (late) after surgery at the last follow-up visit (mean follow-up: 29.5 months).
Motor severity, assessed by the Unified Huntington's Disease Rating Scale-Motor Score, UHDRS-MS), was significantly reduced at both early and late post-surgery time points (mean improvement 54.3% and 44.1%, respectively). Functional capacity (UHDRS-Functional Capacity Score) was also significantly improved at both post-surgery time points (mean 75.5% and 73.3%, respectively), whereas incapacity (UHDRS-Independence Score) improvement reached significance at early post-surgery only (mean 37.3%). Long term significant improvement of motor symptom severity (≥ 20 % from baseline) was observed in 61.5 % of the patients. Chorea and dystonia improved, whereas effects on dysarthria and swallowing were variable. Parkinsonism did not improve. Linear regression analysis showed that preoperative motor severity predicted motor improvement at both post-surgery time points. The most serious adverse event was device infection and cerebral abscess, and one patient died suddenly of unclear cause, 4 years after surgery.
This study shows that bilateral DBS of the GPi effectively reduces the severity of drug-resistant hyperkinetic movement disorders such as present in ChAc.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
ABSTRACT
Background
Friedreich's ataxia usually occurs before the age of 25. Rare variants have been described, such as late‐onset Friedreich's ataxia and very‐late‐onset Friedreich's ataxia, ...occurring after 25 and 40 years, respectively. We describe the clinical, functional, and molecular findings from a large series of late‐onset Friedreich's ataxia and very‐late‐onset Friedreich's ataxia and compare them with typical‐onset Friedreich's ataxia.
Methods
Phenotypic and genotypic comparison of 44 late‐onset Friedreich's ataxia, 30 very late‐onset Friedreich's ataxia, and 180 typical Friedreich's ataxia was undertaken.
Results
Delayed‐onset Friedreich's ataxia (late‐onset Friedreich's ataxia and very‐late‐onset Friedreich's ataxia) had less frequently dysarthria, abolished tendon reflexes, extensor plantar reflexes, weakness, amyotrophy, ganglionopathy, cerebellar atrophy, scoliosis, and cardiomyopathy than typical‐onset Friedreich's ataxia, along with less severe functional disability and shorter GAA expansion on the smaller allele (P < 0.001). Delayed‐onset Friedreich's ataxia had lower scale for the assessment and rating of ataxia and spinocerebellar degeneration functional scores and longer disease duration before wheelchair confinement (P < 0.001). Both GAA expansions were negatively correlated to age at disease onset (P < 0.001), but the smaller GAA expansion accounted for 62.9% of age at onset variation and the larger GAA expansion for 15.6%. In this comparative study of late‐onset Friedreich's ataxia and very‐late‐onset Friedreich's ataxia, no differences between these phenotypes were demonstrated.
Conclusion
Typical‐ and delayed‐onset Friedreich's ataxia are different and Friedreich's ataxia is heterogeneous. Late‐onset Friedreich's ataxia and very‐late‐onset Friedreich's ataxia appear to belong to the same clinical and molecular continuum and should be considered together as “delayed‐onset Friedreich's ataxia.” As the most frequently inherited ataxia, Friedreich's ataxia should be considered facing compatible pictures, including atypical phenotypes (spastic ataxia, retained reflexes, lack of dysarthria, and lack of extraneurological signs), delayed disease onset (even after 60 years of age), and/or slow disease progression.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
After more than 50 years of treating Parkinson's disease with l-DOPA, there are still no guidelines on setting the optimal dose for a given patient. The dopamine transporter type 1, now known as ...solute carrier family 6 (neurotransmitter transporter), member 3 (SLC6A3) is the most powerful determinant of dopamine neurotransmission and might therefore influence the treatment response. We recently demonstrated that methylphenidate (a dopamine transporter inhibitor) is effective in patients with Parkinson's disease with motor and gait disorders. The objective of the present study was to determine whether genetic variants of the dopamine transporter type 1-encoding gene (SLC6A3) are associated with differences in the response to treatment of motor symptoms and gait disorders with l-DOPA and methylphenidate (with respect to the demographic, the disease and the treatment parameters and the other genes involved in the dopaminergic neurotransmission). This analysis was part of a multicentre, parallel-group, double-blind, placebo-controlled, randomized clinical trial of methylphenidate in Parkinson's disease (Protocol ID:2008-005801-20; ClinicalTrials.gov:NCT00914095). We scored the motor Unified Parkinson's Disease Rating Scale and the Stand-Walk-Sit Test before and after a standardized acute l-DOPA challenge before randomization and then after 3 months of methylphenidate treatment. Patients were screened for variants of genes involved in dopamine metabolism: rs28363170 and rs3836790 polymorphisms in the SLC6A3 gene, rs921451 and rs3837091 in the DDC gene (encoding the aromatic L-amino acid decarboxylase involved in the synthesis of dopamine from l-DOPA), rs1799836 in the MAOB gene (coding for monoamine oxidase B) and rs4680 in the COMT gene (coding for catechol-O-methyltransferase). Investigators and patients were blinded to the genotyping data throughout the study. Eighty-one subjects were genotyped and 61 were analysed for their acute motor response to l-DOPA. The SLC6A3 variants were significantly associated with greater efficacy of l-DOPA for motor symptoms. The SLC6A3 variants were also associated with greater efficacy of methylphenidate for motor symptoms and gait disorders in the ON l-DOPA condition. The difference between motor Unified Parkinson's Disease Rating Scale scores for patients with different SLC6A3 genotypes was statistically significant in a multivariate analysis that took account of other disease-related, treatment-related and pharmacogenetic parameters. Our preliminary results suggest that variants of SLC6A3 are genetic modifiers of the treatment response to l-DOPA and methylphenidate in Parkinson's disease. Further studies are required to assess the possible value of these genotypes for (i) guiding l-DOPA dose adaptations over the long term; and (ii) establishing the risk/benefit balance associated with methylphenidate treatment for gait disorders.
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