Bashan N, Iancu T C, Lerner A, Fraser D, Potashnik R, Moses S W
Pediatr Res. 1981 Apr;15(4 Pt 1):299-303. doi: 10.1203/00006450-198104000-00002.
A four-year-old Israeli Arab boy was found to have glycogen accumulation in both liver and muscle without clinical symptoms. Liver phosphorylase kinase (PK) activity was 20% of normal, resulting in undetectable activity of phosphorylase a. Muscle PK activity was about 25% of normal, resulting in a marked decrease of phosphorylase a activity. Two sisters showed a similar pattern, whereas one brother had normal PK activity. The patient's liver protein kinase activity was normal Addition of exogenous protein kinase did not affect PK activity, whereas exogenous PK restored phosphorylase activity to normal. These findings indicate that these patients are affected by a rare variant of PK deficiency, which involves both muscle and liver and which apparently is not sex linked. It is possible that this defect represents an unusual mutation of a subunit of the phosphorylase kinase enzyme.
一名4岁的以色列阿拉伯男孩被发现肝脏和肌肉中均有糖原蓄积，但无临床症状。肝脏磷酸化酶激酶（PK）活性为正常的20%，导致磷酸化酶a活性检测不到。肌肉PK活性约为正常的25%，导致磷酸化酶a活性显著降低。两名姐妹表现出类似模式，而一名兄弟的PK活性正常。患者的肝脏蛋白激酶活性正常。添加外源蛋白激酶不影响PK活性，而外源PK可将磷酸化酶活性恢复至正常。这些发现表明，这些患者受一种罕见的PK缺乏变体影响，该变体累及肌肉和肝脏，且显然与性别无关。这种缺陷可能代表磷酸化酶激酶亚基的一种异常突变。
