Neurodevelopmental Disorder-Craniofacial Dysmorphism-Cardiac Defect-Skeletal Anomalies Syndrome Due to 9q21.3 Microdeletion, is also known as 9q21.3 microdeletion syndrome. An important gene associated with Neurodevelopmental Disorder-Craniofacial Dysmorphism-Cardiac Defect-Skeletal Anomalies Syndrome Due to 9q21.3 Microdeletion is HNRNPK (Heterogeneous Nuclear Ribonucleoprotein K). Affiliated tissues include bone and tongue, and related phenotypes are hypotonia and long palpebral fissure