Abstract
Since our initial description of deficient activity of hepatic dephsophorylase kinase and increased liver glycogen [Science 153: 1535, 1966], we have studied a total of 7 patients with this condition. Five of these patients have been reported [J.clin.Invest. 48: 705, 1969]. They and the 2 additional patients, brothers age 4 and 1 ½ years, always had greatly reduced liver phosphorylase activity (about 10% of control) that could be increased to normal by addition of kinase. This rules out phophorylase deficiency, or type VI glycogenosis. On the basis of ‘one enzymatic defect for one type of glycogenosis’, we called deficient kinase activity type IX glycogen storage disease. In type IX glycogenosis there is no hyperlipemia, hypoglycemia, acetonuria, or evidence of X-chromosomal inheritance. There is a typical light and electron microscopic appearance of the liver. Biochemically, the skeletal muscle is normal as is the blood sugar response to glucagon. In contrast, in a girl with hepatomegaly and low hepatic phosphorylase activity there is increased glycogen concentration in the skeletal muscle as well as the liver and the glucagon tolerance curve is flat. In her skeletal muscle the amount of total phosphorylase is normal but all of it is in the inactive form. Phosphoylase kinase is present in this muscle but we found evidence for deficient activity of 3′4′-AMP dependent kinase that normally activates phosphorylas kinase [J.biol.Chem. 243: 3763, 1968]. Therefore, we have named this new type of glycogen storage disease with a hitherto undescribed enzymatic deficiency type X glycogenosis. (Supported by NIH grants No. AM 13903 and No. RR 00123.)
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Hug, G., Schubert, W. & Chuck, G. Low Phosphorylase Activity: A Symptom but not a Diagnosis. Pediatr Res 4, 452 (1970). https://doi.org/10.1203/00006450-197009000-00072
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DOI: https://doi.org/10.1203/00006450-197009000-00072