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md90
08-25-2006, 08:32 PM
A 2-year-old boy is brought to the pediatrician by his mother, who is visibly upset. The mother reports that her son has recently been biting his fingers and scratching his face incessantly. She says he was normal for the first few months of his life but has become increasingly irritable since about 3 months of age. The mother also mentions that here son often has "orange-colored sand" in his diapers. Laboratory studies reveal a serum uric acid level of 55 mg/dL. Urinalysis reveals crystaluria and microscopic hematuria.

1. What is the most likely diagnosis?
2. What is the biochemical defect in this condition?
3. What is the function of the deficient enzyme?
4. What is the most appropriate treatment for this condition?
5. What other conditions can be expected if this disease is not treated?

MDiva
08-25-2006, 09:38 PM
1. Lesch-Nyhan syndrome
2. defect is HPRT
3. purine salvage
4. treat the behavior issues and treat the excess uric acid...allopurinol?
5. ???

md90
08-25-2006, 09:59 PM
1. Lesch-Nyhan syndrome
2. defect is HPRT
3. purine salvage
4. treat the behavior issues and treat the excess uric acid...allopurinol?
5. ???

Great job MDiva!!!!
5. for this question.. think about what happens if there is an excess of uric stone in systems... two places that I think about is kidney (stones and renal failure) and joints (gout leading to arthritis)...

follow-up question:
1. What does allopurinol inhibit? and How?

IMG SURVIVOR
08-25-2006, 10:02 PM
allopurinoll inhibits xantine oxidasa

md90
08-25-2006, 10:53 PM
allopurinoll inhibits xantine oxidasa

How??? it prevents hypoxanthine into going to xanthine which forms uric acid... (xanthine oxidase is the enzyme)

ZWobble
08-25-2006, 11:08 PM
Its also a noncompetitive inhibitor.

md90
08-25-2006, 11:51 PM
thank you zwobble