
October 2, 1999
Diagnosis and Symptoms
Question from Bedford, Quebec, Canada:
My sister’s 8 year old son has sugar in his urine but no sign of sugar in his blood. The doctors have been doing tests but don’t know what’s wrong. My sister is worried. Do you think the sugar in his urine is normal?
Answer:
If the blood sugar has been found to be repeatedly normal, and renal diseases have been excluded, it could be a form of renal glycosuria, whose definition is the excretion of excessive amounts of sugar (glucose) in the urine in presence of normal filtered loads of glucose. It’s not diabetes at all nor related to it. It is actually an abnormality in renal handling of glucose (tubular glucose transport) and can be found isolated or in association with other metabolic abnormalities under the name of Fanconi’s syndrome. Renal glycosuria is inherited as an autosomal recessive trait (family history positive) and the definitive diagnosis must exclude other causes of sugar in the urine. Familial renal glycosuria is a benign disease that has no need of any antidiabetic treatment.
MS