A novel missense mutation in SLC5A2 encoding SGLT2 underlies autosomal-recessive renal glucosuria and aminoaciduria

Our findings confirm that mutations in SLC5A2 result in autosomal-recessive FRG. The severe glucosuria in homozygotes for the K321R mutation highlights the importance of the eighth SGLT2 transmembrane domain for normal glucose transport. We suggest that the generalized aminoaciduria accompanying FRG is a consequence of the severe impairment in glucose reabsorption, and is probably not directly related to the SGLT2 mutation. The exact role of the aberrant glucose transport in the pathogenesis of aminoaciduria remains to be established.