My son has shown high levels of sugar in two urine tests which were days apart. I believe that my husband has renal glucosuria. (He has always tested positive for glucosuria, and diabetes is always ruled out.)

My son’s blood is now being tested. but he has not yet been given a glucose tolerance test or fasting test. The doctor wants to go through the “steps”. How would you suggest we proceed to have this situation evaluated in light of the family history?

Renal glucosuria is a benign condition if it exists with no other evidence of renal tubular reabsorption problems, and it is usually inherited as an autosomal recessive characteristic.

In your son’s case, I think that the first step is to do a fasting blood sugar determination. If the level is less than 110mg/dl [6.1 mmol] then by definition his glucosuria is not due to diabetes. Although, if you still feel concerned, you might ask about an antibody test (call 1-800-425-8361 for details). However, I don’t think that this would be necessary unless there is other evidence suggestive of diabetes such as weight loss, thirst, and frequent urination

It is much more likely that your son’s glucosuria is due to the same problem as his father’s. This glucosuria can sometimes be a part of a wider spectrum or renal tubular disorders including various forms of renal tubular acidosis, phosphate losing types that lead to a low serum phosphorus and a variety of aminoacidurias. The investigation of all of this can be rather elaborate, but, in view of your husband’s apparently benign history, I would not start on it unless there were some other clinical indications such as poor growth. Anyway, talk to the doctor about this too.

I hope this didn’t sound too complicated.

DOB