In this group of six diseases (frequency: 1: 8, 500) the ammonia detoxification is impaired. Ammonia is a toxic substance that is normally converted to urea in the liver and excreted in the urine.
In those affected, ammonia accumulates in the blood and, above all, causes impairments to the brain, which are manifested by convulsions, neurological symptoms, mental retardation and disturbances of consciousness. The treatment is difficult and includes a lifelong low-protein, high-calorie, high-carbohydrate diet and various medications.
In cystinuria (not to be confused with cystinosis!) Certain amino acids, especially cystine, can not be passed through the small intestinal cells and urinary canals. This inherited disease occurs in one in 10, 000 children. The most important and usually only symptom are recurring kidney stones, as the corresponding amino acids accumulate in the urine and thereby precipitate.
Often enough for treatment, a high fluid intake, whereby the urine is greatly diluted; otherwise medication can be given.