Hyperphosphatasia with Impaired Intellectual Development Syndrome 2, is also known as glycosylphosphatidylinositol biosynthesis defect 6. An important gene associated with Hyperphosphatasia with Impaired Intellectual Development Syndrome 2 is PIGO (Phosphatidylinositol Glycan Anchor Biosynthesis Class O). Affiliated tissues include bone marrow and heart, and related phenotypes are intellectual disability and hypotonia