Cells co-expressing 1:1 WT:M653I and 1:1 WT:S809R GRIN2A, however, showed a decrease in glutamate EC50 and a significant reduction of ~ 70% and ~ 45% in maximal current compared with cells co-expressing 1:1 WT:E58Ter, respectively (WT:M653I vs. WT:E58Ter: p < 0.0001; WT:S809R vs. WT:E58Ter: p = 0.0002; Fig. 3B, C), demonstrating that the DD/ID-linked variants, M653I and S809R, exert a dominant-negative effect on NMDAR function, whereas the epilepsy-linked variant, A727T, and the SCZ-linked variants, Y698C and E58Ter, do not. The gene discussed is GRIN2A; the disease is epilepsy.