UNRELIABILITY OF PLATELET GLUCOSE-6-PHOSPHATASE FOR THE DIAGNOSIS OF GLYCOGEN-STORAGE-DISEASE TYPE IA

The diagnosis of glycogen storage disease type Ia currently uses enzym e analysis of liver tissue. This requires liver biopsy in the at-risk neonate or fetus. Conflicting reports have appeared in the literature on the use of peripheral platelet glucose-6-phosphatase activity for t he diagnosis of this disorder. We have applied a sensitive radiometric assay system to the measurement of glucose-6-phosphatase activity in peripheral platelets. Two families with affected members were analysed , revealing no differences in glucose-6-phosphatase activity as compar ed with control values. Platelet measurement of glucose-6-phosphatase does not appear to be useful for the diagnosis of glycogen storage dis ease type Ia.