Biochemistry Which enzyme is deficient in Mc Ardle’s disease? A Liver phosphorylase deficiency B Muscle phosphorylase deficiency C Lysosomal alpha-1, 4 glucosidase deficiency D G6PD deficiency 💡 Explanation Which enzyme is deficient in Mc Ardle's disease? ✓ Correct Answer: B. Muscle phosphorylase deficiency