The kidneys play a critical role in maintaining glucose homeostasis. Under normal renal tubular function, most of the glucose filtered from the glomeruli is reabsorbed in the proximal tubules, leaving only trace amounts in the urine. Glycosuria can occur as a symptom of generalized proximal tubular dysfunction or when the reabsorption threshold is exceeded or the glucose threshold is reduced, as seen in familial renal glycosuria (FRG). FRG is characterized by persistent glycosuria despite normal blood glucose levels and tubular function and is primarily associated with mutations in the