A urea cycle issue is an inherited disorder that results in a deficiency of one of the six enzymes in the urea cycle. These enzymes remove ammonia from the blood circulation. The urea cycle includes a series of processes in which nitrogen, a waste product of protein digestion, is changed to a compound called urea and removed from the blood. Usually, the urea is ousted from the body through the urine. In urea cycle problem, nitrogen develops in the blood in the form of ammonia, an incredibly unsafe substance, leading to hyperammonemia or an increase in blood ammonia. Ammonia then reaches the brain through the blood, where it can cause brain damage.