A group of rare diseases due to genetic mutations that cause the absence or deregulation of enzymes or proteins involved in cellular metabolism. Deficiency of these enzymes can cause abnormalities in the metabolism of proteins, carbohydrates or lipids and results in the accumulation of toxic molecules for the body.
Such diseases occur in less than 1/2000 people and most of them are diagnosed in infancy-childhood, but some can occur in adolescence or adulthood.
The dietary recommendations are analogous to endogenous diseases as it is also necessary to use appropriate medical supplements for normal growth and life.