GABRG1 encodes the gamma-1 subunit of GABA(A) receptors, which are heteropentameric ligand-gated chloride channels activated by the inhibitory neurotransmitter GABA 1. As a component of these receptors, GABRG1 facilitates chloride ion influx across the postsynaptic membrane, reducing neuronal excitability and suppressing nerve transmission 1. GABRG1 is prominently expressed in brain reward circuitry and shows particular importance in GABAergic synaptic transmission and inhibitory synapse assembly. Genetic variation in GABRG1 has been robustly associated with alcohol use disorder (AUD) across multiple populations. In European Americans, markers in the GABRG1 haplotype block showed greater association with alcohol dependence than adjacent GABRA2 markers, with evidence suggesting additive genetic contributions 2. In two population isolates (Finnish Caucasians and Plains Indians), GABRG1 haplotypes and SNPs were significantly associated with AUD independent of GABRA2 3. In African Americans, combined GABRG1-GABRA2 haplotypes demonstrated significant associations with alcohol dependence 4. Individual SNPs in GABRG1 also associate with level of response to alcohol and drinking patterns 5. Beyond alcoholism, GABRG1 variants have been implicated in externalizing behavior development, with GG genotype carriers showing increased vulnerability to maladaptive peer influences from childhood through early adulthood 6. GABRG1 is also listed among candidate genes for trigeminal neuralgia 7. These findings highlight GABRG1's role in both normal GABAergic neurotransmission and disease susceptibility.