Epileptic encephalopathies are a phenotypically and genetically heterogeneous group of severe epilepsies accompanied by intellectual disability and other neurodevelopmental features1-6. Using next generation sequencing, we identified four different de novo mutations in KCNA2, encoding the potassium channel KV1.2, in six patients with epileptic encephalopathy (one mutation recurred three times independently). Four individuals presented with febrile and multiple afebrile, often focal seizure types, multifocal epileptiform discharges strongly activated by sleep, mild-moderate intellectual disability, delayed speech development and sometimes ataxia. Functional studies of the two mutations associated with this phenotype revealed an almost complete loss-of-function with a dominant-negative effect. Two further individuals presented with a different and more severe epileptic encephalopathy phenotype. They carried mutations inducing a drastic gain-of-function effect leading to permanently open channels. These results establish KCNA2 as a novel gene involved in human neurodevelopmental disorders by two different mechanisms, predicting either hyperexcitability or electrical silencing of KV1.2-expressing neurons.
Objective:To determine the phenotypic spectrum caused by mutations in GRIN1 encoding the NMDA receptor subunit GluN1 and to investigate their underlying functional pathophysiology.Methods:We collected molecular and clinical data from several diagnostic and research cohorts. Functional consequences of GRIN1 mutations were investigated in Xenopus laevis oocytes.Results:We identified heterozygous de novo GRIN1 mutations in 14 individuals and reviewed the phenotypes of all 9 previously reported patients. These 23 individuals presented with a distinct phenotype of profound developmental delay, severe intellectual disability with absent speech, muscular hypotonia, hyperkinetic movement disorder, oculogyric crises, cortical blindness, generalized cerebral atrophy, and epilepsy. Mutations cluster within transmembrane segments and result in loss of channel function of varying severity with a dominant-negative effect. In addition, we describe 2 homozygous GRIN1 mutations (1 missense, 1 truncation), each segregating with severe neurodevelopmental phenotypes in consanguineous families.Conclusions:De novo GRIN1 mutations are associated with severe intellectual disability with cortical visual impairment as well as oculomotor and movement disorders being discriminating phenotypic features. Loss of NMDA receptor function appears to be the underlying disease mechanism. The identification of both heterozygous and homozygous mutations blurs the borders of dominant and recessive inheritance of GRIN1-associated disorders.
Summary Despite contrary recommendations by expert opinion and international guidelines phenobarbital remains the most widely prescribed anticonvulsant worldwide. Although associated connective tissue disorders were described in a timely way after its introduction, the association between plantar fibromatosis—also called Ledderhose syndrome—and phenobarbital seems not to be well known in general. Our case series uniquely demonstrates that continuous phenobarbital treatment leads to recurrent plantar fibromatosis and may result in long‐term disability and numerous unnecessary operations. In general, the association between connective tissue disorders and phenobarbital most prominently appears in adult patients of northern European descent. However, our case series and data from the literature suggest that patient groups less susceptible to connective tissue disorders may as well develop Ledderhose syndrome or other associated syndromes as Dupuytren's contractures, frozen shoulder, Peyronie's disease or complex regional pain syndrome in the course of phenobarbital treatment.
Objectives: This report focuses on the design and methods of the 3-centre clinical study of the Transregional Collaborative Research Centre ‘Inflammatory Cardiomyopathy – Molecular Pathogenesis and Therapy’, which aims to establish a comprehensive research registry on the diagnostics, therapy and disease outcomes of patients with inflammatory cardiomyopathy (CMi). The study goals are to investigate specific disease sub-entities and to develop standardised strategies for diagnostics and treatment. Methods: All consecutive patients with clinically suspected CMi, post-myocarditic cardiomyopathy and acute myocarditis are included in the research registry. Cardiopulmonary functional tests, clinical and patient data are obtained at baseline and subsequent readmission appointments and are linked to allow for prospective follow-up. Co-morbidities, quality of life, health- related behaviour and sociodemographic variables are ascertained using uniform self-administered questionnaires. Present Status: By May 2008, 2,061 cases had been included in the research registry (1,300 data-sets completed). At registration, 335 patients were diagnosed with CMi. The mean age was 50 ± 13 years and the mean ejection fraction was 39.9 ± 15.8%. Conclusions: The broad range of the acquired molecular-biological, histological, immunohistological, clinical and patient data makes this the most comprehensive research registry on patients with CMi to date.
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