Genetic convergence of developmental and epileptic encephalopathies and intellectual disability

Aim To determine whether genes that cause developmental and epileptic encephalopathies (DEEs) are more commonly implicated in intellectual disability with epilepsy as a comorbid feature than in intellectual disability only. Method We performed targeted resequencing of 18 genes commonly implicated in DEEs in a cohort of 830 patients with intellectual disability (59% male) and 393 patients with DEEs (52% male). Results We observed a significant enrichment of pathogenic/likely pathogenic variants in patients with epilepsy and intellectual disability (16 out of 159 in seven genes) compared with intellectual disability only (2 out of 671) (p