Publications by authors named "Shiva Ganesan"

Article Synopsis
  • EEG is crucial for diagnosing and managing genetic epilepsies in children, yet the relationship between quantitative EEG features and neurological outcomes is not well understood.* -
  • The study analyzed EEG data from children with specific genetic variants, used a control group, and created models to compare EEG features like the alpha-delta ratio to predict diagnoses and neurological outcomes.* -
  • Results showed significant differences in the alpha-delta ratio between genetic epilesies and controls, with high accuracy in predicting diagnoses, allowing for the identification of potential biomarkers for different genetic disorders in epilepsy.*
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  • Speech and language disorders have a significant genetic component, but research specifically focusing on linguistic differences as unique conditions has been limited.
  • An analysis of over 52,000 pediatric individuals revealed that these disorders are most common between ages 2 and 5, with only 12% of stuttering cases accurately coded in medical records.
  • The study identified key genetic disorders linked to these disorders and found notable associations between specific genetic variants and conditions like aphasia and speech delays related to hearing loss.
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Purpose: An early genetic diagnosis can guide the time-sensitive treatment of individuals with genetic epilepsies. However, most genetic diagnoses occur long after disease onset. We aimed to identify early clinical features suggestive of genetic diagnoses in individuals with epilepsy through large-scale analysis of full-text electronic medical records.

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The insights gained from big data and omics approaches have transformed the field of childhood genetic epilepsy. With an increasing number of individuals receiving genetic testing for seizures, we are provided with an opportunity to identify clinically relevant subgroups and extract meaningful observations from this large-scale clinical data. However, the volume of data from electronic medical records and omics (e.

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Speech and language disorders are known to have a substantial genetic contribution. Although frequently examined as components of other conditions, research on the genetic basis of linguistic differences as separate phenotypic subgroups has been limited so far. Here, we performed an in-depth characterization of speech and language disorders in 52,143 individuals, reconstructing clinical histories using a large-scale data mining approach of the Electronic Medical Records (EMR) from an entire large paediatric healthcare network.

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Article Synopsis
  • Copy number variants (CNVs) are linked to neurodevelopmental disorders, particularly those involving seizures or epilepsy, prompting researchers to analyze genetic data from large groups of individuals with seizure disorders and epilepsy.
  • The study identified 25 significant genetic loci associated with seizures, of which 22 are newly discovered, including various deletions and duplications at specific chromosomal locations.
  • Further analysis showed connections between these loci and a range of neuropsychiatric conditions, offering insights into the clinical implications of these variants for epilepsy diagnosis and treatment.
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Background: The developmental and epileptic encephalopathies (DEEs) are the most severe group of epilepsies which co-present with developmental delay and intellectual disability (ID). DEEs usually occur in people without a family history of epilepsy and have emerged as primarily monogenic, with damaging rare mutations found in 50% of patients. Little is known about the genetic architecture of patients with DEEs in whom no pathogenic variant is identified.

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Background: The epilepsies are highly heritable conditions that commonly follow complex inheritance. While monogenic causes have been identified in rare familial epilepsies, most familial epilepsies remain unsolved. We aimed to determine (1) whether common genetic variation contributes to familial epilepsy risk, and (2) whether that genetic risk is enriched in familial compared with non-familial (sporadic) epilepsies.

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Making a specific diagnosis in neurodevelopmental disorders is traditionally based on recognizing clinical features of a distinct syndrome, which guides testing of its possible genetic etiologies. Scalable frameworks for genomic diagnostics, however, have struggled to integrate meaningful measurements of clinical phenotypic features. While standardization has enabled generation and interpretation of genomic data for clinical diagnostics at unprecedented scale, making the equivalent breakthrough for clinical data has proven challenging.

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Article Synopsis
  • * A majority of participants exhibit neurodevelopmental issues (95%) and seizures (89%), with common seizure types and early onset, underscoring the severity of STXBP1-related conditions.
  • * Despite identifying frequent genetic variants, no specific associations were found between these variants and particular clinical syndromes, indicating a high level of variability in the clinical presentation of STXBP1-related disorders.
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While genetic studies of epilepsies can be performed in thousands of individuals, phenotyping remains a manual, non-scalable task. A particular challenge is capturing the evolution of complex phenotypes with age. Here, we present a novel approach, applying phenotypic similarity analysis to a total of 3251 patient-years of longitudinal electronic medical record data from a previously reported cohort of 658 individuals with genetic epilepsies.

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Objective: The clinical features of epilepsy determine how it is defined, which in turn guides management. Therefore, consideration of the fundamental clinical entities that comprise an epilepsy is essential in the study of causes, trajectories, and treatment responses. The Human Phenotype Ontology (HPO) is used widely in clinical and research genetics for concise communication and modeling of clinical features, allowing extracted data to be harmonized using logical inference.

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Purpose: Pathogenic variants in SCN2A cause a wide range of neurodevelopmental phenotypes. Reports of genotype-phenotype correlations are often anecdotal, and the available phenotypic data have not been systematically analyzed.

Methods: We extracted phenotypic information from primary descriptions of SCN2A-related disorders in the literature between 2001 and 2019, which we coded in Human Phenotype Ontology (HPO) terms.

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Article Synopsis
  • The Human Phenotype Ontology (HPO) was established in 2008 to standardize the description and analysis of phenotypic abnormalities in human diseases, and has become a global reference for phenotype data.
  • Recent updates to the HPO include expansions in various medical fields, with improvements such as the seizure subontology aligning with international epilepsy guidelines, demonstrating their clinical validity.
  • Ongoing efforts focus on harmonizing phenotypic definitions across the HPO and other ontologies, enhancing computational tools for cross-species disease research, and translating the HPO into indigenous languages for broader accessibility.
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  • 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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  • This study investigates the genetic factors contributing to childhood epilepsies and examines longitudinal data from electronic medical records (EMR) to analyze these conditions over time.
  • By mapping neurological diagnoses to standardized terminology and tracking patient encounters, researchers observed the associations between specific genes and epilepsy-related symptoms.
  • The findings suggest that EMR data can effectively reveal significant gene-phenotype connections and may improve future clinical decision-making and outcome studies.
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  • Febrile infection-related epilepsy syndrome (FIRES) is a severe form of epilepsy that arises after a febrile infection and is characterized by refractory status epilepticus.
  • A study analyzed the genetic makeup of 50 individuals with FIRES through exome sequencing and found no pathogenic variants in known genes linked to epilepsy or neurodevelopmental disorders.
  • HLA sequencing in participants did not reveal any significant alleles, suggesting that FIRES has a distinct genetic basis compared to other similar conditions, indicating a need for innovative research to uncover its causes.
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Objective: To define the phenotypic spectrum of phosphatidylinositol glycan class A protein (PIGA)-related congenital disorder of glycosylation (PIGA-CDG) and evaluate genotype-phenotype correlations.

Methods: Our cohort encompasses 40 affected males with a pathogenic PIGA variant. We performed a detailed phenotypic assessment, and in addition, we reviewed the available clinical data of 36 previously published cases and assessed the variant pathogenicity using bioinformatical approaches.

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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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