Answer and Discussion of Quiz Set: N-009

6.    Which of the following disease is not a lysosomal storage disease?

A.  Pompe's disease

B.  McArdle's disease

C.  Farber's disease

D.  Gauche's disease

E.  Nieman-Pick diseas

Answer and Discussion: The answer is (B). Although both Pompe's disease and McArdle's disease are glycogen storage diseases, the biochemical defect in Pompoe's disease is deficiency of the monomeric a-1,4-glucosidase which is a lysosomal acid maltase which makes it a lysosomal storage disease. The biochemical defect of McArdle's disease is deficiency of the muscle isoform of glycogen phosphorylase that convert glycogen into glucose-1-phosphate which will lead to accumulation of free glycogen (not within lysosome). Farber's disease, Gauche's disease, and Nieman-Pick are all characterized by accumulation of lipids and are all lysosomal disorders.