Morphologic characteristics of the placenta in glycogen storage disease type II (alpha-1,4-glucosidase deficiency).

Five placentas from infants with enzymatically diagnosed glycogen storage disease type II (three from midtrimester abortions, two from term deliveries) were studied by light and electron microscopy. On routine histologic examination with hematoxylin and eosin staining, storage cells were identifiable in the connective tissue of the amnion. These cells provide the means to diagnose this glycogen storage disease prior to the development of clinical symptoms. Electron microscopy, even in the midtrimester placenta, shows typical membrane-bound, glycogen-filled vacuoles in the villous endothelium and stromal cells. These vacuoles can provide confirmation of glycogen storage in cases of prenatal enzymatic diagnosis and therapeutic abortion.