Analysis for the molecular mechanism of Inheited GPI Deficiency

糖基磷脂酰肌醇（GPI）是一种糖脂，它将150种蛋白质锚定在细胞表面。至少有27个基因参与GPI锚定蛋白（GPI-AP）的生物合成和转运。许多遗传性GPI缺陷（IGDs）已被发现使用全外显子组测序。IGD患者只有部分缺乏，因为完全缺乏GPI会导致胚胎死亡。IGDs的主要症状包括智力障碍、癫痫和多器官畸形。这些症状的严重程度取决于缺陷的程度和/或受影响基因途径中的位置。在一些IGD患者中观察到高磷酸酶血症。在癫痫发作和肢体残疾的患者中应考虑IGD的可能性。高磷酸酶血症的存在是IGD的有力证据。粒细胞上GPI-AP的流式细胞术分析可用于IGD的检测。应该注意的是，维生素B6有时对癫痫发作有效。

Glycosylphosphatidylinositol (GPI) is a glycolipid, which anchors 150 proteins to the cell surface. There are at least 27 genes involved in the biosynthesis and transport of GPI-anchored proteins (GPI-APs). Many inherited GPI deficiencies (IGDs) have been found using whole-exome sequencing. Patients with IGD have only a partial deficiency because complete GPI deficiency causes embryonic death. The major symptoms of IGDs include intellctual disability, epilepsy, and multiple organ anomalies. These symptoms vary in severity depending upon the degree of the defect and/or position in the pathway of the affected gene. Hyperphosphatasia is observed in some patients with IGDs. The possibility of IGD should be considered in patients with seizures and intellctual disability. The presence of hyperphosphatasia is strong evidence of IGD. Flow cytometric analysis of GPI-APs on granulocytes is useful for the detection of IGD. It should be noted that Vitamin B6 is sometimes effective for seizures.