Loss-of-function mutations in GRIN2A are known to cause seizure disorders, disorders of intellectual development, and speech and language disorders [27–30]; in the largest series of GRIN2A mutations reported to date (n = 284 people), 24% had a documented neuropsychiatric comorbidity, including two cases with schizophrenia [28]. Here, GRIN2A is linked to schizophrenia.