GRIK1 encodes glutamate ionotropic receptor kainate type subunit 1, a cation-permeable ligand-gated ion channel activated by L-glutamate and kainic acid that modulates glutamatergic synaptic transmission and postsynaptic membrane potential regulation. The gene is highly expressed in brain regions governing learning and memory, making it functionally important for cognitive processes. GRIK1 polymorphisms have been associated with multiple neuropsychiatric disorders: rs363504 and rs363538 variants show association with ADHD etiology and treatment response to methylphenidate 1, rs469472 demonstrated nominal association with schizophrenia in both case-control and family-based analyses 2, and the intergenic rs360932 variant correlated with autism spectrum disorder susceptibility in Egyptian children 3. Regarding pharmacogenetics, the rs2832407 polymorphism has been examined in topiramate efficacy for alcohol use disorder, though in a recent controlled trial it showed no significant effect on treatment response 4. Mechanistically, rs2832407 genotype differentially modulates GRIK1 antisense-2 expression and topiramate's effects on neural excitatory activity in iPSC-derived neurons 5. Beyond psychiatric contexts, elevated GRIK1 expression promotes glioblastoma malignancy and correlates with poor prognosis 6, while the GRIK1-AS1 antisense transcript shows tumor-suppressive functions in gastric cancer 7 and endometriosis 8. These findings establish GRIK1 as a multifunctional gene with disease relevance across neuropsychiatric, oncological, and gynecological conditions.