GRIN2A and epilepsy: We found patients with pathogenic variants in the most common epilepsy genes SCN8A (n = 4), SCN2A (n = 3), SCN1A (n = 2), KCNQ2 (n = 2) and STXBP1, GRIN2A, CHRNA4 (n = 1 each), accounting for 70% of all presumed disease-causing variants (Table 2).