This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Disorders of Amino acid Metabolism, Subject name: Pediatrics
Blood spot Tandem mass spectrometry can be used in the diagnosis of all the following disorders EXCEPT? 
Select and explain. 
A. Lesch Nyhan disease, B. Fatty acid oxidation defects, C. Mitochondrial disorders, D. Propionic Acidemia
A: Lesch Nyhan disease
Answer: A: Lesch Nyhan disease 
Explanation: Tandem mass spectrometry used in the diagnosis of: Fatty acid oxidation defects Mitochondrial defects Organic acidemias Aminoacidopathies Urea cycle disorders.