The function of SLC6A12 (solute carrier family 6 member 12, Ensembl gene identifier ENSG00000111181) is as follows. Transporter that mediates cellular uptake of betaine and GABA in a sodium- and chloride-dependent process (PubMed:7589472). May have a role in regulation of GABAergic transmission in the brain through the reuptake of GABA into presynaptic terminals, as well as in osmotic regulation. Probably also involved in renal and hepatic osmotic regulation (By similarity). {ECO:0000250|UniProtKB:P31651, ECO:0000269|PubMed:7589472}.