Inborn errors of carbohydrate metabolism
Inborn errors of metabolism can affect the catabolism and anabolism of carbohydrates, sometimes causing minor problems such as in lactose intolerance, others cause life threatening diseases such as Von Gierke's Disease. The carbohydrates that account for a major portion of the human diet are composed of three principal monosaccharides: glucose, fructose and galactose.
Source: Wikipedia — Inborn errors of carbohydrate metabolism (CC BY-SA 4.0)