Definition:

Familial renal glucosuria (FRG) is a rare autosomal recessive disorder of the kidney characterized by decreased renal tubular resorption of glucose from the urine in the absence of hyperglycemia and any other signs of tubular dysfunction. The vast majority of affected individuals are asymptomatic, but there is a rare propensity to develop hypoglycemia and hypovolemia. FRG is associated with mutations in the SGLT2 gene.