Defective Enzymes in the Individual
Urea cycle disorder is composed of a group of inherited diseases. These diseases make it hard for the body to remove waste products resulting from protein breakdown. Proteins are broken down into amino acids which are useful in the body (Foschi et al., 2015). Excess amino acids are converted into nitrogen and consequently into urea which is removed from the body through urine. The abnormal high levels of plasma ammonia (hyperammonemia) in the neonate body was as a result of N-acetylglutamate synthase deficiency. N-acetylglutamate gene is responsible for the production of N-acetylglutamate synthase enzyme. If this enzyme is unavailable or insufficient, the urea cycle is compromised and nitrogen is not efficiently broken (Foschi et al., 2015). This leads to accumulation of excess nitrogen inform of ammonia in the bloodstream. Since the brain is very sensitive to excess ammonia, the neonate experienced focal seizures. Deficiency of N-acetylglutamate synthase enzyme is caused by mutation in its gene.
Increase in Glutamine Levels
Due to hyperammonemia (high plasma ammonia levels) in the neonate, there was increased level of glutamine in the bloodstream. This is because glutamine is synthesized from ammonia. Glutamine is an amino acid used in protein biosynthesis (Cruzat, Macedo, Noel, Curi, and Newsholme, 2018). The body can synthesize sufficient level of glutamine. Glutamine increases the amount of plasma growth hormone which helps the neonate to stay strong. This leads to an increase in immune system making the body to fight the illness. Glutamine also buffers ammonia, thus, monitoring the status of plasma ammonia in the bloodstream (Cruzat et al., 2018). Glutamine acts as a reservoir for waste nitrogen. Therefore, increase in nitrogenous waste increases the level of glutamine in the blood stream. In nitrogen metabolism, glutamine intake in the liver regulates urea cycle activities due to conversion to glutamate ammonia by the glutamine synthase (Lee et al., 2016). The glutamate formed can form N-acetylglutamate which is responsible for the neonate disorder.
Acute hyperammonemia in neonates is life threating and therefore, it needs to be treated. Urea cycle carried out in the liver. Proteins are not stored in the body unlike fats and carbohydrates. Since ammonia results from breakdown of proteins, in neonate patient with hyprerammonemia, dietary protein in the baby formula and breastmilk should be regulated (Alfadhel et al., 2016). This can be done through re-introduction of essential amino acids, restriction of protein intake dietary and elimination of ammonia. In neonates, restriction of proteins in their diet is challenging because they need them for growth and development. The neonate should not be fed on breastmilk which contains proteins for 24-48hrs. Instead patient should be given glucose solution (dextrose 10%) (Alfadhel et al., 2016). This ensures that the neonate remains hydrated at a rate of 8-10 mg/kg/min. At times, insulin can be added so as to maintain glycemia levels at normal range. When the ammonia level in the bloodstream drops below 100µmol/L, protein is slowly reintroduced slowly.