An abnormality in the ornithine cycle would result in elevation of what substance?

An abnormality in the ornithine cycle, also known as the urea cycle, typically leads to an accumulation of ammonia in the bloodstream. The primary function of the urea cycle is to convert ammonia, which is a toxic byproduct of protein metabolism, into urea, a less toxic compound that can be safely excreted in urine. When there is a defect in any of the enzymes involved in this cycle, the conversion process is impaired, resulting in elevated levels of ammonia.

Ammonia is particularly harmful because it can cross the blood-brain barrier and cause neurological damage, making it critical to identify and manage issues related to the ornithine cycle promptly. This condition is often associated with various genetic disorders that affect the enzymes responsible for the urea cycle's efficiency.

While substances such as urea, citrulline, and glutamine are also related to the cycle, their elevation occurs under different circumstances. Urea would not be elevated in an ornithine cycle defect since the cycle's purpose is to produce urea from ammonia. Citrulline levels might be altered depending on the specific defect in the cycle, but the critical concern in the case of an abnormality is primarily the accumulation of ammonia. Glutamine does