Zusammenfassung
Die Anwendung von Hochdurchsatz-Sequenziermethoden für ein populationsbasiertes genomisches Neugeborenenscreening (gNBS) bietet zahlreiche Chancen für die Verbesserung der ...Bevölkerungsgesundheit. Ein solches würde ermöglichen, die Diagnose zahlreicher genetischer Erkrankungen bereits in einem frühen, präsymptomatischen Stadium zu stellen, und böte große Flexibilität bei der Auswahl und Erweiterung von Zielkrankheiten. National und international werden daher Anstrengungen unternommen, um die ethischen, rechtlichen, sozialen, psychologischen und technischen Aspekte des gNBS zu untersuchen. Neben den vielen Chancen existieren auch zahlreiche Herausforderungen und noch offene Fragen: Wann und wie sollten Erziehungsberechtigte über ein solches Screening informiert werden? Auf welche Krankheiten sollte gescreent werden? Wie soll mit Zufallsbefunden oder der Feststellung einer genetischen Veranlagung umgegangen werden? Sollen die Daten langfristig gespeichert werden und, wenn ja, wie kann dies sicher geschehen? Unter der Voraussetzung einer angemessenen Rechtsgrundlage und eines transparenten Einwilligungsprozesses hat das genomische Neugeborenenscreening das Potenzial, die Art und Weise, wie wir angeborene Krankheiten diagnostizieren, grundlegend zu verändern. Es gibt jedoch noch viel zu tun. Um ein gutes Verständnis und eine ausreichende Akzeptanz des gNBS bei allen Beteiligten zu erreichen und so den Nutzen für die Bevölkerung zu maximieren, ist ein öffentlicher Diskurs über die Möglichkeiten und Grenzen des gNBS von zentraler Bedeutung. Dieser Beitrag hat das Ziel, einen Überblick über die innovativen technischen Entwicklungen in der Humangenetik, nationale und internationale Forschungsansätze sowie über Chancen und Herausforderungen bei der Entwicklung eines genomischen Neugeborenenscreenings zu geben.
ObjectiveTo investigate reported extreme temperature-related catastrophic events and associated mortality on the European continent including the Russian Federation.DesignCross-sectional respecting ...Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) criteria.SettingsData source: Emergency Events Database (EM-DAT).ParticipantsSearch criteria: location—European continent including Russian Federation, time—years 1988 until 2019 (close of database 12 July 2019), catastrophic events—extreme temperatures.Primary outcome measuresNumbers of heat waves, cold waves, severe winter conditions and associated number of deaths, overall, and per country and year, respecting STROBE criteria.ResultsThe most frequent type of the 243 events recorded in EM-DAT were cold waves (54.7%). However, cold waves and severe winter conditions only accounted for 6460 deaths (4.5%), while heat waves were associated with 137 533 deaths (95.5%). The five most severe heat waves in 2003, 2006, 2010, 2013 and 2015 were associated with a total of 135 089 deaths. The most severe heat waves were geographically distributed over the Russian Federation (2010), as well as France, Italy, Spain and Germany, each in 2003.ConclusionAlthough cold waves are more frequently reported in EM-DAT, heat waves are the major cause for temperature-related deaths. In order to better protect the public, it is important to address resiliency and vulnerability of populations at risk and age groups.
Pathogenic variants in
, encoding for the voltage-gated potassium channel K
1.2, have been identified as the cause for an evolving spectrum of neurological disorders. Affected individuals show ...early-onset developmental and epileptic encephalopathy, intellectual disability, and movement disorders resulting from cerebellar dysfunction. In addition, individuals with a milder course of epilepsy, complicated hereditary spastic paraplegia, and episodic ataxia have been reported. By analyzing phenotypic, functional, and genetic data from published reports and novel cases, we refine and further delineate phenotypic as well as functional subgroups of
-associated disorders. Carriers of variants, leading to complex and mixed channel dysfunction that are associated with a gain- and loss-of-potassium conductance, more often show early developmental abnormalities and an earlier onset of epilepsy compared to individuals with variants resulting in loss- or gain-of-function. We describe seven additional individuals harboring three known and the novel
variants p.(Pro407Ala) and p.(Tyr417Cys). The location of variants reported here highlights the importance of the proline(405)-valine(406)-proline(407) (PVP) motif in transmembrane domain S6 as a mutational hotspot. A novel case of self-limited infantile seizures suggests a continuous clinical spectrum of
-related disorders. Our study provides further insights into the clinical spectrum, genotype-phenotype correlation, variability, and predicted functional impact of
variants.
TUBA1A tubulinopathy is a rare neurodevelopmental disorder associated with brain malformations as well as early-onset and intractable epilepsy. As pathomechanisms and genotype-phenotype correlations ...are not completely understood, we aimed to provide further insights into the phenotypic and genetic spectrum. We here present a multicenter case series of ten unrelated individuals from four European countries using systematic MRI re-evaluation, protein structure analysis, and prediction score modeling. In two cases, pregnancy was terminated due to brain malformations. Amongst the eight living individuals, the phenotypic range showed various severity. Global developmental delay and severe motor impairment with tetraparesis was present in 63% and 50% of the subjects, respectively. Epilepsy was observed in 75% of the cases, which showed infantile onset in 83% and a refractory course in 50%. One individual presented a novel TUBA1A-associated electroclinical phenotype with evolvement from early myoclonic encephalopathy to continuous spike-and-wave during sleep. Neuroradiological features comprised a heterogeneous spectrum of cortical and extracortical malformations including rare findings such as cobblestone lissencephaly and subcortical band heterotopia. Two individuals developed hydrocephalus with subsequent posterior infarction. We report four novel and five previously published TUBA1A missense variants whose resulting amino acid substitutions likely affect longitudinal, lateral, and motor protein interactions as well as GTP binding. Assessment of pathogenic and benign variant distributions in synopsis with prediction scores revealed sections of variant enrichment and intolerance to missense variation. We here extend the clinical, neuroradiological, and genetic spectrum of TUBA1A tubulinopathy and provide insights into residue-specific pathomechanisms and genotype-phenotype correlations.
Succinic semialdehyde dehydrogenase deficiency (SSADHD) is a rare, monogenic disorder affecting the degradation of the main inhibitory neurotransmitter γ-amino butyric acid (GABA). Pathogenic ...variants in the
gene that cause an enzymatic dysfunction of succinic semialdehyde dehydrogenase (SSADH) lead to an accumulation of potentially toxic metabolites, including γ-hydroxybutyrate (GHB). Here, we present a patient with a severe phenotype of SSADHD caused by a novel genetic variant c.728T > C that leads to an exchange of leucine to proline at residue 243, located within the highly conserved nicotinamide adenine dinucleotide (NAD)
binding domain of SSADH. Proline harbors a pyrrolidine within its side chain known for its conformational rigidity and disruption of protein secondary structures. We investigate the effect of this novel variant in vivo, in vitro, and in silico. We furthermore examine the mutational spectrum of all previously described disease-causing variants and computationally assess all biologically possible missense variants of
to identify mutational hotspots.
Succinic semialdehyde dehydrogenase deficiency (SSADH-D) is a genetic disorder that results from the aberrant metabolism of the neurotransmitter γ-amino butyric acid (GABA). The disease is caused by ...impaired activity of the mitochondrial enzyme succinic semialdehyde dehydrogenase. SSADH-D manifests as varying degrees of mental retardation, autism, ataxia, and epileptic seizures, but the clinical picture is highly heterogeneous. So far, there is no approved curative therapy for this disease. In this review, we briefly summarize the molecular genetics of SSADH-D, the past and ongoing clinical trials, and the emerging features of the molecular pathogenesis, including redox imbalance and mitochondrial dysfunction. The main aim of this review is to discuss the potential of further therapy approaches that have so far not been tested in SSADH-D, such as pharmacological chaperones, read-through drugs, and gene therapy. Special attention will also be paid to elucidating the role of patient advocacy organizations in facilitating research and in the communication between researchers and patients.
The widespread use of high-throughput sequencing techniques is leading to a rapidly increasing number of disease-associated variants of unknown significance and candidate genes. Integration of ...knowledge concerning their genetic, protein as well as functional and conservational aspects is necessary for an exhaustive assessment of their relevance and for prioritization of further clinical and functional studies investigating their role in human disease. To collect the necessary information, a multitude of different databases has to be accessed and data extraction from the original sources commonly is not user-friendly and requires advanced bioinformatics skills. This leads to a decreased data accessibility for a relevant number of potential users such as clinicians, geneticist, and clinical researchers. Here, we present aRgus (https://argus.urz.uni-heidelberg.de/), a standalone webtool for simple extraction and intuitive visualization of multi-layered gene, protein, variant, and variant effect prediction data. aRgus provides interactive exploitation of these data within seconds for any known gene of the human genome. In contrast to existing online platforms for compilation of variant data, aRgus complements visualization of chromosomal exon-intron structure and protein domain annotation with ClinVar and gnomAD variant distributions as well as position-specific variant effect prediction score modeling. aRgus thereby enables timely assessment of protein regions vulnerable to variation with single amino acid resolution and provides numerous applications in variant and protein domain interpretation as well as in the design of in vitro experiments.
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(1) Background: Phenotypic diversity and long-term health outcomes of individuals with urea cycle disorders (UCDs) have been described in detail. However, there is limited information on the burden ...on affected families. (2) Methods: To evaluate the family burden in parents with children suffering from UCDs, we used validated questionnaires. Socio-demographic characteristics were evaluated, and an adapted version of the Parental Need Scale for Rare Diseases questionnaire was used. The survey was conducted in families of UCD patients cared for at the University Children's Hospital Heidelberg. (3) Results: From April to November 2021, 59 participants were interviewed (mothers
= 34, fathers
= 25). The affected patients most frequently suffered from ornithine transcarbamylase deficiency (OTC-D) (female
= 12, male
= 12), followed by argininosuccinate synthetase deficiency (ASS-D,
= 13) and argininosuccinate lyase deficiency (ASL-D,
= 8). About one-third of the participants were "dissatisfied" or "extremely dissatisfied" with health professionals' disease knowledge. In addition, 30% of the participants reported a medium or high need for "additional information on the development of their children", and 44% reported a medium or high need "for information on available services". A majority of 68% reported a need for additional support regarding services such as support groups (42%) or psychological counseling (29%). (4) Conclusions: Our study indicates that there is an unmet need for sufficient information about the development of children with UCDs, as well as for information about available support services for families with UCD patients. Furthermore, the results highlight the importance of establishing or improving family-centered care approaches. This pilot study may serve as a template for the assessment of the family burden associated with other inherited metabolic diseases.
Abstract
Neurotransmitter deficiencies are rare neurological disorders with clinical onset during childhood. The disorders are caused by genetic defects in the enzymes involved in synthesis, ...degradation, or transport of neurotransmitters or by defects in the cofactor biosynthesis such as tetrahydrobiopterin (BH
4
). With the newly described DNAJC12 deficiency, a chaperon-associated neurotransmitter disorder, the pathophysiological spectrum has been broadened. All deficiencies result in a lack of monoamine neurotransmitters, especially dopamine and its products, with a subset leading to decreased levels of serotonin. Symptoms can occur already in the neonatal period. Classical signs are hypotonia, movement disorders, autonomous dysregulations, and impaired development. Diagnosis depends on quantitative detection of neurotransmitters in cerebrospinal fluid, since peripheral markers in blood or urine are less reliable. Treatment is based on supplementation of the missing neurotransmitter precursors or restoring deficient cofactors for endogenous enzymatic synthesis. In recent years, knowledge about this orphan group of diseases increased substantially among clinicians. However, the difficult task of integrating clinical symptoms and laboratory values still leads to a critical delay in diagnosis and therapy for patients. This review aims at enhancing the understanding of neurotransmitter disorders and should help practicing clinicians to choose useful diagnostic steps on the way to a valid diagnosis.
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