Figure 1. Distinctive laboratory findings in Fabry disease. A. Electron µgraph showing the vascular endothelium of a small vessel from a patient with Fabry disease. Note the electron-dense vesicles (lysosomes) in the endothelium containing undegraded glycosphingolipid. The progressive lysosomal accumulation in the vascular endothelium leads to ischemia and infarction of these vessels. B. Electrocardiogram of a 41-year-old man with classic Fabry disease showing sinus bradycardia with short PR interval (88 msec) and left ventricular hypertrophy with QRS widening and a repolarization abnormality.