Significant advances in genomic technologies over the past 15 years have revolutionized gene discovery across a broad spectrum of human genetic disorders. Arguably, some of the greatest impacts have been in severe neurological and neurodevelopmental disorders, including the developmental and epileptic encephalopathies (DEEs),1,2 where de novo, pathogenic variants account for a large proportion of affected individuals.3,4 Genome-wide technologies, including chromosome microarray (CMA) and exome or genome sequencing, permit the identification of copy number and sequence variants across the genome without a prior hypothesis about candidate genomic regions or specific genes.