A 7-year-old child complained of frequent muscle cramps during play. A muscle biopsy revealed accumulation of glycogen in the skeletal muscle cells and a lack of muscle phosphorylase. Which form of glycogenosis is this?

Question

Quizplus · Accepted Answer

Type V glycogenosis, also known as McArdle disease, is caused by muscle phosphorylase deficiency. Patients present with muscle cramps. In these patients, the blood level of lactic acid does not rise after exercise, because the enzyme deficiency prevents anaerobic glycolysis in the muscle cells.

A 7-Year-Old Child Complained of Frequent Muscle Cramps During Play