Case Study:


A 46-year-old male presents to the emergency department with severe right toe pain. The patient was in usual state of health until early in the morning when he woke up with severe pain in his right big toe. The patient denies any trauma to the toe and no previous history of such pain in other joints. He did say that he had a “few too many” beers with the guys last night. On examination, he was found to have a temperature of 100.80F (38.20C) and in moderate distress secondary to the pain in his right toe. The right big toe was swollen, warm, red and exquisitely tender. The remainder of the exam was normal. Synovial (joint) fluid was obtained and revealed rod- or needle-shaped crystals.


1. What is the likely diagnosis??




2. How would you make a definite diagnosis??

            Check for Uric Acid crystals in synovial (joint) fluid


3. What is the biochemistry of this disorder??

            Increased conversion of purine bases to Uric Acid

            Decreased excretion of Uric Acid by the kidneys


4. Define the following terms:



                        Xanthine oxidase inhibitor



                        Enzyme responsible for purine salvage; purine bases à nucleotides



Decreased HGPRT resulting in mental retardation and self destructive behavior; symptoms include increased Uric Acid levels


            Xanthine Oxidase:

Enzyme that catalyzes the final steps in purine degradation to produce Uric Acid



© Sturm 2019

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