Mutations in the GRIN2A gene, which encodes the GluN2A (glutamate [NMDA] receptor subunit epsilon-1) subunit of the N-methyl-d-aspartate receptor, have been identified in patients with epilepsy-aphasia spectrum disorders, idiopathic focal epilepsies with centrotemporal spikes, and epileptic encephalopathies with severe developmental delay.
Whole-exome sequencing with a trio analysis (affected child compared to unaffected parents) was performed and identified a novel de novo missense mutation in GRIN2A, c.2449A>G, p.Met817Val, as the likely cause of the refractory epilepsy and global developmental delay.