Genetics of movement disorders in the next-generation sequencing era

2016 ◽  
Vol 31 (4) ◽  
pp. 458-470 ◽  
Author(s):  
Simone Olgiati ◽  
Marialuisa Quadri ◽  
Vincenzo Bonifati
Keyword(s):  
Next Generation Sequencing ◽  
Movement Disorders ◽  
Next Generation ◽  
Generation Sequencing

scholarly journals Clinical and neuroimaging phenotypes of genetic parkinsonism from infancy to adolescence

Brain ◽  
2019 ◽  
Vol 143 (3) ◽  
pp. 751-770 ◽  
Author(s):  
Hugo Morales-Briceño ◽  
Shekeeb S Mohammad ◽  
Bart Post ◽  
Alessandro F Fois ◽  
Russell C Dale ◽  
...  
Keyword(s):  
Next Generation Sequencing ◽  
Movement Disorders ◽  
Early Onset ◽  
Genetic Disorders ◽  
Phenotypic Characterization ◽  
Imaging Features ◽  
Next Generation ◽  
Phenotypic Spectrum ◽  
Inherited Mutations ◽  
Generation Sequencing

Abstract Genetic early-onset parkinsonism presenting from infancy to adolescence (≤21 years old) is a clinically diverse syndrome often combined with other hyperkinetic movement disorders, neurological and imaging abnormalities. The syndrome is genetically heterogeneous, with many causative genes already known. With the increased use of next-generation sequencing in clinical practice, there have been novel and unexpected insights into phenotype-genotype correlations and the discovery of new disease-causing genes. It is now recognized that mutations in a single gene can give rise to a broad phenotypic spectrum and that, conversely different genetic disorders can manifest with a similar phenotype. Accurate phenotypic characterization remains an essential step in interpreting genetic findings in undiagnosed patients. However, in the past decade, there has been a marked expansion in knowledge about the number of both disease-causing genes and phenotypic spectrum of early-onset cases. Detailed knowledge of genetic disorders and their clinical expression is required for rational planning of genetic and molecular testing, as well as correct interpretation of next-generation sequencing results. In this review we examine the relevant literature of genetic parkinsonism with ≤21 years onset, extracting data on associated movement disorders as well as other neurological and imaging features, to delineate syndromic patterns associated with early-onset parkinsonism. Excluding PRKN (parkin) mutations, >90% of the presenting phenotypes have a complex or atypical presentation, with dystonia, abnormal cognition, pyramidal signs, neuropsychiatric disorders, abnormal imaging and abnormal eye movements being the most common features. Furthermore, several imaging features and extraneurological manifestations are relatively specific for certain disorders and are important diagnostic clues. From the currently available literature, the most commonly implicated causes of early-onset parkinsonism have been elucidated but diagnosis is still challenging in many cases. Mutations in ∼70 different genes have been associated with early-onset parkinsonism or may feature parkinsonism as part of their phenotypic spectrum. Most of the cases are caused by recessively inherited mutations, followed by dominant and X-linked mutations, and rarely by mitochondrially inherited mutations. In infantile-onset parkinsonism, the phenotype of hypokinetic-rigid syndrome is most commonly caused by disorders of monoamine synthesis. In childhood and juvenile-onset cases, common genotypes include PRKN, HTT, ATP13A2, ATP1A3, FBX07, PINK1 and PLA2G6 mutations. Moreover, Wilson’s disease and mutations in the manganese transporter are potentially treatable conditions and should always be considered in the differential diagnosis in any patient with early-onset parkinsonism.

scholarly journals Genetic landscape of pediatric movement disorders and management implications

2018 ◽  
Vol 4 (5) ◽  
pp. e265 ◽  
Author(s):  
Dawn Cordeiro ◽  
Garrett Bullivant ◽  
Komudi Siriwardena ◽  
Andrea Evans ◽  
Jeff Kobayashi ◽  
...  
Keyword(s):  
Next Generation Sequencing ◽  
Movement Disorder ◽  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Movement Disorders ◽  
Genetic Diagnosis ◽  
Next Generation ◽  
Targeted Next Generation Sequencing ◽  
Whole Exome ◽  
Generation Sequencing

ObjectiveTo identify underlying genetic causes in patients with pediatric movement disorders by genetic investigations.MethodsAll patients with a movement disorder seen in a single Pediatric Genetic Movement Disorder Clinic were included in this retrospective cohort study. We reviewed electronic patient charts for clinical, neuroimaging, biochemical, and molecular genetic features. DNA samples were used for targeted direct sequencing, targeted next-generation sequencing, or whole exome sequencing.ResultsThere were 51 patients in the Pediatric Genetic Movement Disorder Clinic. Twenty-five patients had dystonia, 27 patients had ataxia, 7 patients had chorea-athetosis, 8 patients had tremor, and 7 patients had hyperkinetic movements. A genetic diagnosis was confirmed in 26 patients, including in 20 patients with ataxia and 6 patients with dystonia. Targeted next-generation sequencing panels confirmed a genetic diagnosis in 9 patients, and whole exome sequencing identified a genetic diagnosis in 14 patients.ConclusionsWe report a genetic diagnosis in 26 (51%) patients with pediatric movement disorders seen in a single Pediatric Genetic Movement Disorder Clinic. A genetic diagnosis provided either disease-specific treatment or effected management in 10 patients with a genetic diagnosis, highlighting the importance of early and specific diagnosis.

scholarly journals Paroxysmal Movement Disorders

2021 ◽  
Vol 12 ◽  
Author(s):  
Susan Harvey ◽  
Mary D. King ◽  
Kathleen M. Gorman
Keyword(s):  
Next Generation Sequencing ◽  
Movement Disorders ◽  
Clinical Phenotype ◽  
Single Gene ◽  
Copy Number Variant ◽  
Genomic Research ◽  
Next Generation ◽  
Causative Gene ◽  
Gene Testing ◽  
Generation Sequencing

Paroxysmal movement disorders (PxMDs) are a clinical and genetically heterogeneous group of movement disorders characterized by episodic involuntary movements (dystonia, dyskinesia, chorea and/or ataxia). Historically, PxMDs were classified clinically (triggers and characteristics of the movements) and this directed single-gene testing. With the advent of next-generation sequencing (NGS), how we classify and investigate PxMDs has been transformed. Next-generation sequencing has enabled new gene discovery (RHOBTB2, TBC1D24), expansion of phenotypes in known PxMDs genes and a better understanding of disease mechanisms. However, PxMDs exhibit phenotypic pleiotropy and genetic heterogeneity, making it challenging to predict genotype based on the clinical phenotype. For example, paroxysmal kinesigenic dyskinesia is most commonly associated with variants in PRRT2 but also variants identified in PNKD, SCN8A, and SCL2A1. There are no radiological or biochemical biomarkers to differentiate genetic causes. Even with NGS, diagnosis rates are variable, ranging from 11 to 51% depending on the cohort studied and technology employed. Thus, a large proportion of patients remain undiagnosed compared to other neurological disorders such as epilepsy, highlighting the need for further genomic research in PxMDs. Whole-genome sequencing, deep-sequencing, copy number variant analysis, detection of deep-intronic variants, mosaicism and repeat expansions, will improve diagnostic rates. Identifying the underlying genetic cause has a significant impact on patient care, modification of treatment, long-term prognostication and genetic counseling. This paper provides an update on the genetics of PxMDs, description of PxMDs classified according to causative gene rather than clinical phenotype, highlighting key clinical features and providing an algorithm for genetic testing of PxMDs.

Labordiagnostik bei gastrointestinalen Tumoren

2020 ◽  
Vol 11 (05) ◽  
pp. 232-238
Author(s):  
Marcus Kleber
Keyword(s):  
Next Generation Sequencing ◽  
Kolorektales Karzinom ◽  
Next Generation ◽  
Generation Sequencing

ZUSAMMENFASSUNGDas kolorektale Karzinom (KRK) ist einer der häufigsten malignen Tumoren in Deutschland. Einer frühzeitigen Diagnostik kommt große Bedeutung zu. Goldstandard ist hier die Koloskopie. Die aktuelle S3-Leitlinie Kolorektales Karzinom empfiehlt zum KRK-Screening den fäkalen okkulten Bluttest. Für das Monitoring von Patienten vor und nach Tumorresektion werden die Messung des Carcinoembryonalen Antigens (CEA) und der Mikrosatellitenstabilität empfohlen. Für die Auswahl der korrekten Chemotherapie scheint derzeit eine Überprüfung des Mutationsstatus, mindestens des KRAS-Gens und des BRAF-Gens, sinnvoll zu sein. Eine Reihe an neuartigen Tumormarkern befindet sich momentan in der Entwicklung, hat jedoch noch nicht die Reife für eine mögliche Anwendung in der Routinediagnostik erreicht. Den schnellsten Weg in die breite Anwendung können Next-Generation-Sequencing-basierte genetische Tests finden.

Sign in / Sign up

Export Citation Format

Share Document