Multiple Congenital Anomalies-Hypotonia-Seizures Syndrome 2, also known as glycosylphosphatidylinositol biosynthesis defect 4, is related to hypotonia and paroxysmal nocturnal hemoglobinuria, and has symptoms including myoclonic seizures An important gene associated with Multiple Congenital Anomalies-Hypotonia-Seizures Syndrome 2 is PIGA (Phosphatidylinositol Glycan Anchor Biosynthesis Class A), and among its related pathways/superpathways are Metabolism of proteins and Post-translational modification: synthesis of GPI-anchored proteins. Affiliated tissues include heart and pons, and related phenotypes are hepatomegaly and microcephaly