Danon disease is a rare X-linked genetic disorder presenting typically as a triad of mental retardation, skeletal myopathy, and hypertrophic cardiomyopathy (HCM). Mutations of the lysosome-associated membrane protein 2 (LAMP2) gene lead to impaired lysosomal functioning and the accumulation of intracellular glycogen. Similarly to Pompe disease (glycogen storage disease type II), with which it was initially confused, Danon disease is seen as a glycogen storage disorder, but is not related to α-glucosidase enzyme deficiency.
McLeod, J. M., Fowler, S. J., Cerrone, M., Aizer, A., Chinitz, L. A., Raad, R., & Saric, M. (2019). Multimodality Imaging of Danon Disease in a Patient with a Novel LAMP2 Mutation. CASE, 3(5), 235–238. https://doi.org/10.1016/j.case.2019.04.007