Parents

PIGY deficiency is a rare genetic disease characterized by intellectual disability, developmental delay, and epilepsy, facial dysmorphisms, cataracts and skeletal abnormalities. It is caused by germline mutations in the PIGY gene, which is important for glycosylphosphatidylinositol (GPI) anchor biosynthesis. Over 150 kinds of protein can be attached to the cell membrane via GPI anchor, and so mutations in PIGY lead to the decreased levels of GPI-anchored proteins. GPI-anchored proteins play vital roles in numerous biological processes, such as neuronal development. The prevalence of PIGY deficiency is unknown as it is recently recognized disease, but there have been only 4 patients form two families reported.