Kasapkara Ciğdem Seher, Tümer Leyla, Okur Ilyas, Eminoğlu Tuba, Ezgü Fatih Süheyl, Hasanoğlu Alev
Division of Metabolic Diseases, Department of Pediatrics, Gazi, Turkey.
Turk J Pediatr. 2012 Jan-Feb;54(1):35-7.
Glycogen storage disease type I (GSD I) is an autosomal recessive disorder caused by defects in the glucose-6-phosphatase complex. Deficient activity in the glucose-6-phosphatase-a (G6Pase) catalytic unit characterizes GSD IA and defects in the glucose-6-phosphate transporter protein (G6PC) characterize GSD IB. The main clinical characteristics involve fasting hypoglycemia, hyperuricemia, hyperlactatemia, and hyperlipidemia. Hypercalcemia arose as an unknown problem in GSD I patients, especially in those with insufficient metabolic control. The aim of the present study was to obtain the prevalence of hypercalcemia and to draw attention to the metabolic complications of GSD I patients, including hypercalcemia in poor metabolic control. Hypercalcemia frequency and the affecting factors were studied cross-sectionally in 23 GSD I pediatric subjects. Clinical diagnosis of GSD I was confirmed in all patients either through documentation of deficient G6Pase enzyme activity levels on liver biopsy samples or through G6PC gene sequencing of DNA. Hypercalcemia was detected in 78.3% of patients with GSD I. Different from the previous report about hypercalcemia in a GSD IA patient who had R83H and 341delG mutations, we could not identify any genotype-phenotype correlation in our GSD I patients. Hyperlactatemia and hypertriglyceridemia correlated significantly with hypercalcemia. Furthermore, no differences in serum calcium concentrations could be demonstrated between patients with optimal metabolic control. We observed hypercalcemia in our series of GSD I patients during acute metabolic decompensation. Therefore, we speculate that hypercalcemia should be considered as one of the problems of GSD I patients during acute attacks. It may be related with prolonged lactic acidosis or may be a pseudohypercalcemia due to hyperlipidemia that can be seen in GSD I patients with poor metabolic control.
I型糖原贮积病（GSD I）是一种常染色体隐性疾病，由葡萄糖-6-磷酸酶复合体缺陷引起。葡萄糖-6-磷酸酶-α（G6Pase）催化单元活性不足是GSD IA的特征，而葡萄糖-6-磷酸转运蛋白（G6PC）缺陷是GSD IB的特征。主要临床特征包括空腹低血糖、高尿酸血症、高乳酸血症和高脂血症。高钙血症在GSD I患者中是一个不明原因的问题，尤其是那些代谢控制不佳的患者。本研究的目的是了解高钙血症的患病率，并引起对GSD I患者代谢并发症的关注，包括代谢控制不佳时出现的高钙血症。对23名GSD I儿科患者进行了横断面研究，以探讨高钙血症的发生率及其影响因素。所有患者均通过肝活检样本中G6Pase酶活性水平不足的记录或DNA的G6PC基因测序确诊为GSD I。78.3%的GSD I患者检测到高钙血症。与之前关于一名具有R83H和341delG突变的GSD IA患者高钙血症的报告不同，我们在GSD I患者中未发现任何基因型-表型相关性。高乳酸血症和高甘油三酯血症与高钙血症显著相关。此外，代谢控制最佳的患者之间血清钙浓度无差异。我们在一系列GSD I患者的急性代谢失代偿期间观察到了高钙血症。因此，我们推测高钙血症应被视为GSD I患者急性发作时的问题之一。它可能与长期乳酸酸中毒有关，也可能是代谢控制不佳的GSD I患者中因高脂血症导致的假性高钙血症。
