Doctors have been successfully dealing with the potentially fatal inherited conditions affecting the urea cycle for the last couple of years. The urea cycle uses six enzymes to shunt the nitrogen that builds up as the body processes proteins and other chemicals. If just one of the enzymes fails, a patient gets ammonia, which is damaging to the brain.

The disorder occurs in 1 in 3,000 births to 1 in 40,000 births and is very hard to diagnose. Because of this and the fact that many patients die young, it is very hard to get the incidence data. About the rarity of the disorder tells the fact that in the last twenty five years, over 100 hospitals managed to accumulate only 299 cases. The biggest problem with the disorder is that often no specific set of symptoms mark a child with a disorder of the urea cycle.

Back in 1979, a Baltimore pediatrician, Dr. Saul W. Brusilow thought of using the body's own methods of getting rid of the extra nitrogen. His treatment consisted of combination of two chemicals: sodium phenylacetate and sodium benzoate that was delivered intravenously to reduce ammonia levels.

These two compounds work by pushing ammonia away from the urea cycle, shunting nitrogen out of the body. Instead of urea coming into the liver, the medications would shunt it away. Kidney dialysis could also be used as a part of the treatment. Severe cases are usually waiting for the liver transplant.

The combination treatment is now available in a combination product and has been approved by the U.S. Food and Drug Administration. Mild forms of the disorder can survive for many years now using this product.