Consequently, the fairly frequent inactivating mutations in SGLT5, will not only favourably impact the neutropenia associated with G6PC3 and G6PT deficiency, but they also imply, that using the blood concentration of 1,5-AG as a marker to test for glucose excursions in the diabetic population cannot be trusted in individuals harbouring SGLT5 inactivating mutations. This evidence concerns the gene SLC37A4 and hyperinsulinemic hypoglycemia, familial, 4.