Glycogen storage disease type II
The form that happens during early childhood usually comes to medical attention within the first few months of life. The usual presenting features are having a bigger heart than usual (cardiomelagy, 92%), low ability to resist muscle stretch (hypotonia, 88%), cardiomyopathy (88%), breathing problems (78%), muscle weakness (63%), feeding difficulties (57%) and not enough weight gain (inability to thrive, 50%).