Question

Inherited disorders of purine metabolism is/are: A. Lesch-Nyhan syndrome due to Adenosine deaminase B. Xanthinuria due to xanthine oxidase C. Renal lithiasis due to adenosine deaminase D. Gout due to PRPP synthetase Choose the correct answer from the options given below:

• A. A and B only \
• B. D only \
• C. B and D only \
• D. B and C only

Hint:

Remember: Lesch-Nyhan $=$ HGPRT deficiency. This fact immediately rules out statement A and helps narrow down the choices.

Answer 1

The Correct Option is C

Step 1: Concept Purine metabolism includes both the synthesis and breakdown of adenine and guanine nucleotides. Genetic defects in the enzymes of these pathways cause distinct hereditary clinical disorders.

Step 2: Meaning Evaluating the exact association between each metabolic disorder and its underlying enzyme defect.

Step 3: Analysis * Statement A: Lesch-Nyhan syndrome is an X-linked recessive disorder caused by a deficiency of hypoxanthine-guanine phosphoribosyltransferase (HGPRT), not adenosine deaminase. * Statement B: Xanthinuria is a rare hereditary disorder caused by a deficiency of xanthine oxidase, leading to the accumulation of xanthine and hypoxanthine. * Statement C: Adenosine deaminase deficiency primarily causes Severe Combined Immunodeficiency (SCID), not isolated renal lithiasis. * Statement D: Gout can be caused by inherited overactivity or mutations in PRPP synthetase, which leads to the overproduction of purines and uric acid.

Step 4: Conclusion Thus, statements B and D are the only correct enzyme-disorder pairings. This matches option C. Final Answer: (C)