152 research outputs found

    Monogenic Parkinson's disease and parkinsonism: Clinical phenotypes and frequencies of known mutations.

    Get PDF
    Mutations in seven genes are robustly associated with autosomal dominant (SNCA, LRRK2, EIF4G1, VPS35) or recessive (parkin/PARK2, PINK1, DJ1/PARK7) Parkinson's disease (PD) or parkinsonism. Changes in a long list of additional genes have been suggested as causes for parkinsonism or PD, including genes for hereditary ataxias (ATXN2, ATXN3, FMR1), frontotemporal dementia (C9ORF72, GRN, MAPT, TARDBP), DYT5 (GCH1, TH, SPR), and others (ATP13A2, CSF1R, DNAJC6, FBXO, GIGYF2, HTRA2, PLA2G6, POLG, SPG11, UCHL1). This review summarizes the clinical features of diseases caused by mutations in these genes, and their frequencies. Point mutations and multiplications in SNCA cause cognitive or psychiatric symptoms, parkinsonism, dysautonomia and myoclonus with widespread alpha-synuclein pathology in the central and peripheral nervous system. LRRK2 mutations may lead to a clinical phenotype closely resembling idiopathic PD with a puzzling variety in neuropathology. Mutations in parkin/PARK2, PINK1 or DJ1/PARK7 may cause early-onset parkinsonism with a low risk for cognitive decline and a pathological process usually restricted to the brainstem. Carriers of mutations in the other genes may develop parkinsonism with or without additional symptoms, but rarely a disease resembling PD. The pathogenicity of several mutations remains unconfirmed. Although some mutations occur with high frequency in specific populations, worldwide all are very rare. The genetic cause of the majority of patients with sporadic or hereditary PD remains unknown in most populations. Clinical genetic testing is useful for selected patients. Testing strategies need to be adapted individually based on clinical phenotype and estimated frequency of the mutation in the patient's population

    Heredity in Parkinson's disease. From rare mutations to common genetic risk factors.

    Get PDF
    This study investigated genetic causes of Parkinson's disease (PD) and parkinsonism in southern Sweden. The extensive Lister Family with parkinsonism caused by duplications and triplications of the gene for alpha-synuclein (SNCA) was studied. Clinical, genetic and genealogical data were compiled and evaluated. Thirty-five family members with parkinsonism were identified. They share a characteristic clinical subtype of parkinsonism with marked dysfunction of the autonomic nervous system, behavioral changes and cognitive decline. The clinical phenotype, heredity and genetic background of 132 probands from Southern Sweden with PD or parkinsonism was examined. The SNCA, LRRK2, EIF4G1, VPS35, PINK1, ATXN2 and ATXN3 genes were analyzed in all probands; the PARKIN, PINK1 and DJ1 genes were tested in a subgroup of 23 patients with young onset or marked heredity. DNA from the brain tissue of 7 patients with parkinsonism was also analyzed. Common genetic risk factors in DNA samples collected within this study were analyzed in collaboration with other research groups. Gene screening identified two rare causative mutations, SNCA A53T and LRRK2 N1437H. An additional patient was compound heterozygous for PARKIN R275W and R275Q mutations. Detailed information on their clinical picture is presented. We present the first neuropathological description of a patient with PD and LRRK2 N1437H mutation, showing pronounced ubiquitin and moderate alpha-synuclein pathology. A heterozygous PINK1 G411S mutation was present in two PD patients but showed no clear co-segregation with the disease in their families. Screening of 1,107 patients and controls as well as meta-analysis of published reports from 7,800 individuals revealed that the PINK1 G411S mutation is a rare risk variant with a relatively large effect size (odds ratios 4.06-8.42). One multicenter study confirmed that common variants in the SNCA and MAPT genes modify PD risk, and was large enough to refute gene-gene interaction between the MAPT and SNCA variants. These results suggest that specific mutations in PD-genes cause characteristic disease subtypes. Despite extensive screening and a high proportion of familial cases, known pathogenic mutations could only explain a small proportion of parkinsonism in this cohort. This may indicate that mutations causing parkinsonism in the Scandinavian population remain to be discovered. Alternatively, familial clustering and sporadic occurrence of PD may be explained by combinations of rare variants with relatively large effect size, such as PINK1 G411S

    Myoclonus-dystonia (DYT11, DYT-SGCE) — a channelopathy?

    Get PDF
    Introduction. Kaczyńska et al. reported a family with myoclonus-dystonia (M-D) caused by a truncating SGCE mutation, in which two members had epilepsy. Further, patients had mild psychiatric and developmental deficits.Clinical reflections. Characteristic motor features of M-D include myoclonus, dystonia and tremor. A wide range of additional disease manifestations are known. A few patients with M-D have seizures.Clinical implications. Altered neuronal excitability has been found in the pathogenesis of M-D. This may explain the partial effectiveness of antiepileptics and a lower seizure threshold, and could encourage trials of other membrane stabilisers. Careful clinical observations of seemingly well-known diseases remain important

    A flexible CSMA based MAC protocol for software defined radios

    Get PDF
    In this article, we propose a flexible CSMA based MAC protocol which facilitates research and experimentation using software define radios. The modular architecture allows to employ the protocol on platforms with heterogeneous hardware capabilities and provides the freedom to exchange or adapt the spectrum sensing mechanism without modifying the MAC protocol internals. We discuss the architecture of the protocol and provide structural details of its main components. Furthermore, we present throughput measurements that have been obtained on an example system using host-based spectrum sensing

    Updated Stroke Gene Panels : Rapid evolution of knowledge on monogenic causes of stroke

    Get PDF
    This article updates our previous Stroke Gene Panels (SGP) from 2017. Online Mendelian Inheritance in Man and PubMed were searched. We divided detected genes into two SGP groups, SGP1: genes reported in at least one person with stroke and associated with one or more clinical subgroups: large artery atherosclerotic, large artery non-atherosclerotic (tortuosity, dolichoectasia, aneurysm, non-atherosclerotic dissection or occlusion), cerebral small vessel diseases, cardio-embolic (arrhythmia, heart defect, cardiomyopathy), coagulation dysfunctions (venous thrombosis, arterial thrombosis, bleeding tendency), intracerebral hemorrhage, vascular malformations (cavernoma, arteriovenous malformations) and metabolism disorders; and SGP2: genes related to diseases that may predispose to stroke. We identified 168 SGP1 genes, 70 of these were validated for clinical practice. We also detected 72 SGP2 genes. Nine genes were removed because of conflicting evidence. The number of genes increased from 168 to 240 during 4.5-years, reflecting a dynamic evolution and the need for regular updates for research and clinical use.Peer reviewe

    ChatGPT, LaMDA, and the Hype Around Communicative AI: The Automation of Communication as a Field of Research in Media and Communication Studies

    Get PDF
    The aim of this article is to more precisely define the field of research on the automation of communication, which is still only vaguely discernible. The central thesis argues that to be able to fully grasp the transformation of the media environment associated with the automation of communication, our view must be broadened from a preoccupation with direct interactions between humans and machines to societal communication. This more widely targeted question asks how the dynamics of societal communication change when communicative artificial intelligence—in short: communicative AI—is integrated into aspects of societal communication. To this end, we recommend an approach that follows the tradition of figurational sociology

    Analyzing Trends in Material Culture Evolution—a Case Study of Gravettian Points from Lower Austria and Moravia

    Get PDF
    Identifying, analyzing, and explaining trends in the development of material culture is one of the major concerns in prehistoric archaeology. The traditional recording of data in typologies, however, is not optimal for answering the question of diachronic change because typological data capture variability poorly and are often incompatible with multivariate statistics. To overcome these problems, we present PyREnArA (Python-R-Environment for Artifact Analysis), a trait-based tool that allows for a systematic recording of diversity and variability in a way that is applicable to quantitative analysis and multivariate statistics. Using Gravettian assemblages from Lower Austria and Moravia as a case study, we analyze changes in the morphology as well as the design of lithic projectiles and statistically determine the amount of variation that correlates with the progression of time. We identify a slow trend towards slenderer and more pointed projectiles and a shift from laterally to latero-frontally hafted implements. Most of the analyzed traits, however, appear not to experience selective pressure and seem to be unrelated to the passage of time. We discuss these results with regard to different scales of selection, in particular individual choice vs. macroevolutionary group selection over longer periods of time and thus beyond the realm of individual intend, and we raise questions for future research

    18F-AV-1451 tau PET imaging correlates strongly with tau neuropathology in MAPT mutation carriers

    Get PDF
    Tau positron emission tomography ligands provide the novel possibility to image tau pathology in vivo. However, little is known about how in vivo brain uptake of tau positron emission tomography ligands relates to tau aggregates observed post-mortem. We performed tau positron emission tomography imaging with 18F-AV-1451 in three patients harbouring a p.R406W mutation in the MAPT gene, encoding tau. This mutation results in 3- and 4-repeat tau aggregates similar to those in Alzheimer's disease, and many of the mutation carriers initially suffer from memory impairment and temporal lobe atrophy. Two patients with short disease duration and isolated memory impairment exhibited 18F-AV-1451 uptake mainly in the hippocampus and adjacent temporal lobe regions, correlating with glucose hypometabolism in corresponding regions. One patient died after 26 years of disease duration with dementia and behavioural deficits. Pre-mortem, there was 18F-AV-1451 uptake in the temporal and frontal lobes, as well as in the basal ganglia, which strongly correlated with the regional extent and amount of tau pathology in post-mortem brain sections. Amyloid-β (18F-flutemetamol) positron emission tomography scans were negative in all cases, as were stainings of brain sections for amyloid. This provides strong evidence that 18F-AV-1451 positron emission tomography can be used to accurately quantify in vivo the regional distribution of hyperphosphorylated tau protein

    Small vessel disease in primary familial brain calcification with novel truncating PDGFB variants

    Get PDF
    Introduction. Primary familial brain calcification (PFBC) is a neurodegenerative disease characterised by bilateral calcification in the brain, especially in the basal ganglia, leading to neurological and neuropsychiatric manifestations. White matter hyperintensities (WMH) have been described in patients with PFBC and pathogenic variants in the gene for platelet-derived growth factor beta polypeptide (PDGFB), suggesting a manifest cerebrovascular process. We present below the cases of two PFBC families with PDGFB variants and stroke or transient ischaemic attack (TIA) episodes. We examine the possible correlation between PFBC and vascular events as stroke/TIA, and evaluate whether signs for vascular disease in this condition are systemic or limited to the cerebral vessels. Material and methods. Two Swedish families with novel truncating PDGFB variants, p.Gln140* and p.Arg191*, are described clinically and radiologically. Subcutaneous capillary vessels in affected and unaffected family members were examined by light and electron microscopy. Results. All mutation carriers showed WMH and bilateral brain calcifications. The clinical presentations differed, with movement disorder symptoms dominating in family A, and psychiatric symptoms in family B. However, affected members of both families had stroke, TIA, and/or asymptomatic intracerebral ischaemic lesions. Only one of the patients had classical vascular risk factors. Skin microvasculature was normal. Conclusions. Patients with these PDGFB variants develop microvascular changes in the brain, but not the skin. PDGFB-related small vessel disease can manifest radiologically as cerebral haemorrhage or ischaemia, and may explain TIA or stroke in patients without other vascular risk factors
    • …
    corecore