[Congenital fructose intolerance diagnosed in a 13-year-old boy]. / Wrodzona nietolerancja fruktozy rozpoznana u 13-letniego chlopca.

We describe the case of 13 year old boy who was admitted to the hospital in order to find the reason of hepatomegaly and increased echogenicity observed in sonography. The thorough anamnesis revealed aversion to products containing fructose and thus hereditary fructose intolerance appeared the most probable in this case. The preliminary diagnosis was confirmed by oral fructose tolerance test.