We introduce a cohort of 36 individuals presenting clinical features compatible with the Developmental and Epileptic Encephalopathy caused by SYNGAP1. All cases present heterozygous genetic variants in the SYNGAP1 locus that are predicted to be pathogenic or likely pathogenic (Table 1 and Supplementary Table S1). This evidence concerns the gene SYNGAP1 and developmental and epileptic encephalopathy.