[Disordered glucose-6-phosphate transport as a possible cause of glycogenosis type Ib]

More than ten patients with glycogen-storage disease, which were classified as patients with glycogenosis of the I type--deficiency in glucose-6-phosphatase) on the basis of clinical data and biochemical analyses in vivo, were detected within the last few years. But activity of glucose-6-phosphatase was found to be normal in biopsy of samples of the liver tissue obtained from these patients. This disease was termed as glycogenosis of the Ib type. A hypothesis is advanced, according to which the discrepancy in data on biochemical study of the patients in vivo and in vitro is due to absence of a specific permease in liver tissue, which transfers glucose-6-phosphate from cytosol onto the innesurface of membranes of cytoplasmic network, where glucose-6-phosphatase is located.