Last, new potentially pathogenic variants in GABBR2, SCN1A, TRPC1, ERRFI1, CTXN3, IRX6, and IQCA1 have been identified in GRIN2A‐negative individuals, emphasizing the underlying genetic heterogeneity of LKS. This evidence concerns the gene CTXN3 and developmental and/or epileptic encephalopathy with spike-wave activation in sleep.