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Berkovic, S. F.

Publications and source records attributed to Berkovic, S. F..

4 recordsLinked to original sources

Knowledge Inclusive Machine Learning for Disease Gene Prioritisation

The predictive performance of machine learning models depends on the context available to them. In disease gene prioritisation, this context comprises two forms: specific context from sample-level experimental data, such as gene expression and protein-protein interaction networks, and general context from accumulated and curated biological knowledge capturing established relationships among genes, diseases, and pathways. Neither is sufficient alone: experimental data are sensitive to dataset-specific noise and lack broader biological grounding, while curated knowledge lacks the resolution required for gene-level discrimination. Consequently, most machine learning approaches relying solely on experimental data risk learning spurious correlations rather than underlying biology. Here we introduce Knowledge Inclusive Machine Learning (KIML), a paradigm that integrates both context types within a unified analytical pipeline. KIML combines experimental data with two types of general context: literature-derived representations from PubMed and structured biomedical knowledge graphs. We evaluate the approach on Developmental and Epileptic Encephalopathy and benchmark it against recent methods using publicly available datasets. Performance is assessed using temporal-split evaluation and biological evaluations, including ontology enrichment analysis. KIML consistently outperforms existing approaches, providing improved predictive accuracy and biologically meaningful insights. Furthermore, the framework generates interpretable explanations of gene prioritisation and demonstrates strong generalisability across six additional diseases.

genetics↗

Activating Ras-MAPK pathway variants drive hippocampal clonal competition in human epilepsy

Mesial (a.k.a., medial) temporal lobe epilepsy (MTLE) is the most common focal epilepsy1,2 and, in drug-resistant cases, is treated by surgical removal of the anterior temporal lobe, which often shows neuronal loss and gliosis consistent with hippocampal sclerosis (HS)2. MTLE with HS has minimal contribution from germline genetic variation3, and is associated with prior precipitating insults such as prolonged childhood seizures and head trauma4-6. Somatic variants in Ras-MAPK pathway genes were recently reported in a few MTLE surgical specimens7,8, but their prevalence, clinical relevance, and underlying biological mechanisms remain unknown. Targeted duplex sequencing of hippocampal DNA from 462 surgical resections revealed significant enrichment of deleterious somatic variants in MTLE versus controls, with >40% of MTLE specimens harboring activating Ras-MAPK variants in PTPN11, NF1, BRAF, KRAS, and twelve genes not previously associated with focal epilepsy. Eight Ras-MAPK genes showed positive clonal selection in MTLE. Increased somatic variant burden predicted worse surgical outcome. Somatic Ras-MAPK variants at ultra-low (<0.5%) variant allele fractions were associated with older seizure onset and HS pathology, supporting a late prenatal or postnatal origin. Ras-MAPK variants in MTLE were enriched in cells derived from hippocampal progenitors--neurons, astrocytes, oligodendrocytes--in line with the known neuronal hyperexcitability and seizures induced by Ras-MAPK overactivation9,10; in contrast, Alzheimer disease hippocampi exhibited microglial enrichment of Ras-MAPK variants, consistent with prior reports11. Single-nucleus RNA sequencing showed increased expression of Ras-MAPK genes in neurons and upregulation of pathways mediating neurogenesis and neural development in MTLE. Functional validation of novel, recurrent PTPN11 variants confirmed gain-of-function, while cellular modeling in induced pluripotent stem cells demonstrated proliferative/survival advantages for mutant cells in mosaic culture. Overall, our data suggest that somatic Ras-MAPK variants and acquired risk factors may converge on clonal competition in the hippocampus to modulate epilepsy risk.

genetics↗

Atenolol reduces cardiac-mediated mortality in a genetic mouse model of sudden unexpected death in epilepsy

Sudden Unexpected Death in Epilepsy (SUDEP) is the leading cause of premature mortality in epilepsy. Genetic cardiac risk factors, including loss-of-function KCNH2 variants, have been linked to SUDEP. We hypothesised that seizures and LQTS interact to increase SUDEP risk. To investigate this, we crossed Kcnh2+/- and Gabrg2R43Q/+ mice that model LQTS and genetic epilepsy, respectively. Electrocorticography and electrocardiogram confirmed that Kcnh2+/- mice had a LQTS phenotype, while Gabrg2R43Q/+ mice displayed spontaneous seizures. Double mutant mice (Gabrg2R43Q/+/Kcnh2+/-) had both seizure and LQTS phenotypes that were indistinguishable from the respective single mutant mice. Survival analysis revealed that Gabrg2R43Q/+/Kcnh2+/- mice experienced a disproportionate higher rate of seizure-related death. Long-term oral administration of atenolol, a cardiac-selective {beta}-blocker, significantly improved survival in the Gabrg2R43Q/+/Kcnh2+/- mice. An additional mouse model, Hcn1M294L/+/Kcnh2+/-, based on a HCN1 developmental epileptic encephalopathy variant, also experienced a disproportionately higher rate of premature death that was rescued by atenolol. Kcnh2+/- mice also spent more time in ventricular arrhythmia during proconvulsant-induced seizures. Overall, the data implicates cardiac and loss-of-function KCNH2 variants as an important risk factor, and the potential repurposing of {beta}- blockers as a prevention strategy, for SUDEP in a subset of epilepsy patients.

neuroscience↗

Loss-of-function variants in the cardiac Kv11.1 channel as a genetic biomarker for SUDEP

ObjectiveTo compare the frequency and impact on channel function of KCNH2 variants in SUDEP patients with epilepsy controls comprising patients older than 50 years, a group with low SUDEP risk, and establish loss-of-function KCNH2 variants as predictive biomarkers of SUDEP risk. MethodsWe searched for KCNH2 variants with a minor allele frequency of < 5%. Functional analysis in Xenopus laevis oocytes was performed for all KCNH2 variants identified. ResultsKCNH2 variants were found in 11.1% (10/90) of SUDEP individuals compared to 6.0% (20/332) of epilepsy controls (p = 0.11). Loss-of-function KCNH2 variants, defined as causing > 20% reduction in maximal amplitude, were observed in 8.9% (8/90) SUDEP patients compared to 3.3% (11/332) epilepsy controls suggesting about three-fold enrichment (nominal p = 0.04). KCNH2 variants that did not change channel function occurred at a similar frequency in SUDEP (2.2%; 2/90) and epilepsy control (2.7%; 9/332) cohorts (p > 0.99). Rare KCNH2 variants (< 1% allele frequency) associated with greater loss of function and an [~]11-fold enrichment in the SUDEP cohort (nominal p = 0.03). In silico tools were unable to predict the impact of a variant on function highlighting the need for electrophysiological analysis. ConclusionsThese data show that loss-of-function KCNH2 variants are enriched in SUDEP patients and suggest that cardiac mechanisms contribute to SUDEP risk. We propose that genetic screening in combination with functional analysis can identify loss-of-function KCNH2 variants that could act as biomarkers of an individuals SUDEP risk.

neuroscience↗