11th August 2024

Glycogen storage diseases (GSD)

The glycogen storage diseases are inborn errors of metabolism that lead to issues with glucose processing and energy release.

Muscle symptoms include pain and stiffness following exercise, elevated CK (creatine kinase) and muscle transaminases and myoglobinuria. In McArdle’s, the ‘second wind’ phenomenon may be noted in which after an initial barrier (with fatigue, tachycardia and breathlessness) is surmounted, exercise tolerance improves. This is due to activation of other energy sources (e.g. fatty acids, hepatic glucose production) to supplement ineffective muscle energy release due to myophosphorylase deficiency.