Final Answer:
HGPRT deficiency leads to the conversion of hypoxanthine to uric acid, causing the precipitation of urate crystals in joints and triggering arthritis, specifically gout. Thus, the correct option is b. Uric acid; arthritis.
Step-by-step explanation:
HGPRT (hypoxanthine-guanine phosphoribosyltransferase) plays a crucial role in the salvage pathway of purine metabolism, converting hypoxanthine to inosine monophosphate (IMP) and guanine to guanosine monophosphate (GMP). When HGPRT is deficient, hypoxanthine is not efficiently converted, leading to its accumulation. In the absence of HGPRT, hypoxanthine is instead converted to uric acid. Elevated levels of uric acid can result in the precipitation of urate crystals in joints, which triggers an inflammatory response and leads to a condition known as gout.
Gout is a form of arthritis characterized by sudden, severe attacks of pain, redness, and swelling in joints, commonly affecting the big toe. The deposition of urate crystals in the joints is a hallmark of gout, and the inflammation associated with these crystals contributes to the symptoms of arthritis. Understanding the link between HGPRT deficiency, the accumulation of uric acid, and the development of gout provides insights into the molecular basis of this condition.
In summary, the deficient activity of HGPRT diverts the metabolic pathway towards the production of uric acid, leading to the formation of crystals in joints and triggering the inflammatory response associated with arthritis, specifically gout. This connection between enzyme deficiency and disease highlights the intricate relationship between biochemical pathways and clinical manifestations in the context of purine metabolism.
Thus, the correct option is b. Uric acid; arthritis.