Publications by authors named "Simone Seiffert"

Spinal motor neurons (MNs) represent a highly vulnerable cellular population, which is affected in fatal neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA). In this study, we show that the heterozygous loss of SYT13 is sufficient to trigger a neurodegenerative phenotype resembling those observed in ALS and SMA. SYT13 hiPSC-derived MNs displayed a progressive manifestation of typical neurodegenerative hallmarks such as loss of synaptic contacts and accumulation of aberrant aggregates.

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Recently, variants in , coding for the potassium channel subunit K3.2, have been described as causative for various forms of epilepsy including genetic generalized epilepsy (GGE) and developmental and epileptic encephalopathy (DEE). Here, we report the functional characteristics of three additional variants of uncertain significance and one variant classified as pathogenic.

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Article Synopsis
  • The study investigates a new neurodevelopmental syndrome linked to loss-of-function variants in the ANK2 gene, associated with conditions like intellectual disability and autism.
  • Researchers used CRISPR technology to create human-induced pluripotent stem cells (hiPSCs) with these genetic variants, then differentiated these cells into neurons for further examination.
  • Findings revealed that ANK2-deficient neurons exhibited hyperactivity and lack of synchronization within neuronal networks, along with structural changes that affect their function and adaptability.
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Objective: Fibroblast Growth Factor 12 (FGF12) may represent an important modulator of neuronal network activity and has been associated with developmental and epileptic encephalopathy (DEE). We sought to identify the underlying pathomechanism of FGF12-related disorders.

Methods: Patients with pathogenic variants in FGF12 were identified through published case reports, GeneMatcher and whole exome sequencing of own case collections.

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Article Synopsis
  • The study focuses on Kv3.2, a potassium channel crucial for high-frequency brain firing and efficient action potential generation, examining its genetic variations linked to epilepsy.
  • Researchers analyzed clinical data and functional characteristics of Kv3.2 variants found in patients with different types of epilepsy, including cases like genetic generalized epilepsy and severe developmental epilepsy.
  • Results revealed that out of 18 identified variants, 10 were new and linked to severe epilepsy forms, leading to significant insights about Kv3.2's involvement in epilepsy and its role in regulating brain activity.
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The 2-oxoglutarate dehydrogenase-like (OGDHL) protein is a rate-limiting enzyme in the Krebs cycle that plays a pivotal role in mitochondrial metabolism. OGDHL expression is restricted mainly to the brain in humans. Here, we report nine individuals from eight unrelated families carrying bi-allelic variants in OGDHL with a range of neurological and neurodevelopmental phenotypes including epilepsy, hearing loss, visual impairment, gait ataxia, microcephaly, and hypoplastic corpus callosum.

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Article Synopsis
  • More than 100 genetic causes have been identified in developmental and epileptic encephalopathies (DEEs), but linking these genetic factors to clinical symptoms has been challenging due to the complexity of clinical data.
  • Researchers analyzed data from 846 individuals to find connections between specific genes and clinical features using Human Phenotype Ontology (HPO), identifying significant associations for genes like SCN1A and STXBP1 with specific seizure types and speech delays.
  • The study found that using a semantic similarity approach helps in distinguishing unique phenotypic profiles for various genetic causes, improving the understanding of genetic epilepsies and offering a new way to support evidence of disease causation based on phenotypic analysis.
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Patients with neurofibromatosis type 1 (NF1) have an increased risk for West syndrome (WS), but the underlying mechanisms linking NF1 and WS are unknown. In contrast to other neurocutaneous syndromes, intracerebral abnormalities explaining the course of infantile spasms (IS) are often absent and the seizure outcome is usually favorable. Several studies have investigated a potential genotype-phenotype correlation between and seizure susceptibility, but an association was not identified.

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The developmental and epileptic encephalopathies (DEEs) are heterogeneous disorders with a strong genetic contribution, but the underlying genetic etiology remains unknown in a significant proportion of individuals. To explore whether statistical support for genetic etiologies can be generated on the basis of phenotypic features, we analyzed whole-exome sequencing data and phenotypic similarities by using Human Phenotype Ontology (HPO) in 314 individuals with DEEs. We identified a de novo c.

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Background: The clinical phenotype associated with germline SMARCB1 mutations has as yet not been fully documented. It is known that germline SMARCB1 mutations may cause rhabdoid tumor predisposition syndrome (RTPS1) or schwannomatosis. However, the co-occurrence of rhabdoid tumor and schwannomas in the same patient has not so far been reported.

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