Sequencing of the DNA fragments from schizophrenic patients and healthy control group was conducted to search for a sequence variation in the gene subunit GRIN1 (rs L13266.1) associated with susceptibility to schizophrenia, GRIN2B (rs1806201) associated with the efficacy of neuroleptic and polymorphisms in genes of subunits, which determine NMDA receptor functions—GRIN2A [2150–2152 (AAT)] and GRIN2B—2052–2054 (AAC). The gene discussed is GRIN2B; the disease is schizophrenia.