CD59 and paroxysmal nocturnal hemoglobinuria: Somaticmutation of PIGA leads to paroxysmal nocturnal hemoglobinuria (PNH),19 a disorder involving red blood cell destructiondue to a lack of CD55 and CD59, two GPI-anchored proteins that regulatethe complement system.20 Other anomaliesand clinical features are widespread and correspond to the deletedexpression of PIGA in various tissues, including the brain, liver,heart, and blood cells.19 Patients withPIGL gene mutations suffer from developmental delay, seizures, dysmorphicfeatures, and cranial shape anomalies.