The protein encoded by this gene is an inositol acyltransferase that acylates the inositol ring of phosphatidylinositol. This occurs in the endoplasmic reticulum and is a step in the biosynthesis of glycosylphosphatidylinositol (GPI), which anchors many cell surface proteins to the membrane. Defects in this gene are a cause of the age-dependent epileptic encephalopathy West syndrome as well as a syndrome exhibiting hyperphosphatasia and cognitive disability (HPMRS5). [provided by RefSeq, Jul 2017]