Pax3+/- adults have 100% piebaldism, along with variable penetrance for neural crest (NC)-related persistent truncus arteriosus (PTA) or double outlet right ventricle (DORV) with concomitant ventricular septal defects VSDs [72, 73, 76, 77], congenital hydrocephalus [78], and/or skeletal defects due to abnormal somite morphogenesis [79, 80]. Here, PAX3 is linked to congenital hydrocephalus.