Final answer:
Gene therapy aimed at treating ornithine transcarbamylase deficiency is intended to prevent the buildup of ammonia in the blood, by correcting the enzyme deficiency that impairs the urea cycle.
Step-by-step explanation:
Using gene therapy to correct ornithine transcarbamylase deficiency (OTC) would help prevent the buildup of ammonia in the blood. OTC deficiency is a genetic disorder affecting the urea cycle, where the enzyme ornithine transcarbamylase plays a crucial role in converting ammonia to urea, which can then be excreted from the body. The buildup of ammonia in the body due to OTC deficiency can lead to hyperammonemia, a condition characterized by elevated levels of ammonia in the blood. This condition is toxic and can cause neurological problems and other severe health issues.
The urea cycle consists of five steps that convert ammonia, a byproduct of protein metabolism, to urea which is less harmful and can be excreted through urine. Due to the absence or malfunction of the enzyme ornithine transcarbamylase in individuals with OTC deficiency, ammonia fails to be converted to urea efficiently, leading to its accumulation.
In instances such as the tragic case of Jesse Gelsinger, gene therapy was attempted to correct the genetic defect responsible for OTC deficiency. Unfortunately, complications arose due to the immune response to the viral vector used in the therapy, resulting in his death. However, successful gene therapy holds the potential of restoring the normal function of the urea cycle, thus preventing ammonia toxicity.
The mention of the correct option in the final answer is a). Ammonia