Sugie H, Sugie Y, Nishida M, Ito M, Tsurui S, Suzuki M, Miyamoto R, Igarashi Y
Department of Pediatrics, Hamamatsu University School of Medicine, Japan.
J Child Neurol. 1989 Apr;4(2):95-9. doi: 10.1177/088307388900400203.
We report the case of an 11-year-old mentally retarded boy with recurrent myoglobinuria precipitated after a generalized tonic-clonic convulsion. No hemolysis was noted. Ischemic forearm test revealed no rise of venous lactate, suggesting a metabolic defect in an anaerobic glycolytic pathway. Histochemistry studies of the quadriceps muscle showed a normal appearance, but electron microscopy confirmed a moderate increase of the glycogen content in muscle. Direct measurement of glycolytic enzymes demonstrated a marked decrease of phosphoglycerate kinase (PGK) activity in muscle (4.4% of control mean) and hemolysate (8% of control mean). Enzyme characteristics of PGK from our patient (PGK Hamamatsu) using hemolysate demonstrated that it had normal Michaelis constants (Km), normal thermal stability, and a normal pH curve. The reason that hemolytic anemia was absent is uncertain. We concluded that a systematic enzyme analysis of the glycolytic pathway, especially of PGK, should be performed on myoglobinuric patients who are males, or who have an X-linked inheritance as suggested by the family history.
我们报告了一例11岁智力发育迟缓男孩的病例，该男孩在全身性强直阵挛性惊厥后反复出现肌红蛋白尿。未观察到溶血现象。缺血性前臂试验显示静脉乳酸未升高，提示无氧糖酵解途径存在代谢缺陷。股四头肌的组织化学研究显示外观正常，但电子显微镜证实肌肉中糖原含量中度增加。糖酵解酶的直接测量表明，肌肉中磷酸甘油酸激酶（PGK）活性显著降低（为对照平均值的4.4%），溶血产物中PGK活性也降低（为对照平均值的8%）。使用溶血产物对我们患者的PGK（PGK滨松）进行的酶特性研究表明，其米氏常数（Km）正常、热稳定性正常且pH曲线正常。未出现溶血性贫血的原因尚不确定。我们得出结论，对于男性肌红蛋白尿患者或家族史提示有X连锁遗传的患者，应进行糖酵解途径尤其是PGK的系统酶分析。
