Neurodevelopmental Disorder with or Without Hypotonia, Seizures, and Cerebellar Atrophy, also known as neurodevelopmental disorder with hypotonia and cerebellar atrophy, with or without seizures, is related to hypotonia and coloboma, congenital heart disease, ichthyosiform dermatosis, impaired intellectual development, and ear anomalies syndrome. An important gene associated with Neurodevelopmental Disorder with or Without Hypotonia, Seizures, and Cerebellar Atrophy is PIGG (Phosphatidylinositol Glycan Anchor Biosynthesis Class G (EMM Blood Group)), and among its related pathways/superpathways are Metabolism of proteins and Post-translational modification: synthesis of GPI-anchored proteins. Affiliated tissues include brain, and related phenotypes are seizure and hypotonia