Disease-causing variants in synaptic function genes are a common cause of neurodevelopmental disorders (NDDs) and epilepsy. Here, we describe 14 individuals with de novo disruptive variants in BSN, which encodes the presynaptic protein Bassoon. To expand the phenotypic spectrum, we identified 15 additional individuals with protein-truncating variants (PTVs) from large biobanks. Clinical features were standardized using the Human Phenotype Ontology (HPO) across all 29 individuals, which revealed…
