PIGY deficiency is caused by germline mutation in PIGY. PIGY is the component of the enzyme complex for the first step in GPI anchor biosynthesis. GPI-anchored proteins serve critical functions as adhesion molecules, receptors, complement regulators, enzymes and co-receptors in signal transduction pathways. The main clinical features are intellectual disability, developmental delay, epilepsy, facial dysmorphisms, cataracts and skeletal abnormalities. The prevalence of PIGY deficiency is unknown as it is recently recognized disease. There have been only 4 patients reported. The PIGY gene is located on chromosome 4q22.1, and PIGY deficiency is a autosomal recessive disorder.
PIGY