About a month and a half ago, my three-year old son had a routine urine test which showed high levels of sugar in his urine. After some extensive testing, it was determined that he did not have type 1 diabetes, but that he is one of few people who happen to have high levels of sugar in their urine. We went on to find out that this was, in fact, genetic as two of my father’s brothers had the same thing.

But, just this week, he has started showing excessive thirst and frequent urination due to all of the liquid intake. Is it possible that he could have had a negative test just a month and a half ago and could now actually be diagnosed with diabetes?

I believe that you were referring to a situation whereby your son was found to have glucose in the urine but with normal blood glucose levels. This hereditary condition is called “renal glycosuria” and is typically benign, as you have been told. It is most often described to be inherited in what is called an “autosomal recessive” fashion. This means that both you and your spouse would be carriers (but not have the condition). There are reports of this being transmitted in an “autosomal dominant” manner, which means that either you or your spouse DO have the condition. The odds of passing on an autosomal dominant condition to any fetus is 50%; the odds of passing on an autosomal recessive condition is 25%. If your uncles had this condition, but your father did not and you do not, then this is probably the autosomal recessive form.

Now your child is having other symptoms of diabetes. Could he now truly have developed diabetes AND also has benign renal glycosuria? Sure. This is why urine glucose testing is NOT the best way to diagnose diabetes. Relay your concerns to your pediatrician and let us know what happens.

DS