RT Book, Section A1 Bianchi, Diana W. A1 Crombleholme, Timothy M. A1 D'Alton, Mary E. A1 Malone, Fergal D. SR Print(0) ID 1106402295 T1 22q11.2 Deletion (DiGeorge Syndrome) T2 Fetology: Diagnosis and Management of the Fetal Patient, 2e YR 2015 FD 2015 PB McGraw-Hill Education PP New York, NY SN 978-0-07-144201-5 LK obgyn.mhmedical.com/content.aspx?aid=1106402295 RD 2024/03/29 AB Key PointsMost common microdeletion syndrome reported in humans.22q11.2 deletion is associated with DiGeorge syndrome, velocardiofacial syndrome (VCFS), Opitz G/BBB syndrome, and Cayler cardiofacial syndrome (also known as asymmetric crying facies syndrome).Incidence is 1 in 6000 livebirths.Deletion is associated with specific types of congenital heart disease, including tetralogy of Fallot, truncus arteriosus, absent pulmonary valve, and aortic arch abnormalities.Other associated sonographic findings include growth restriction, nuchal translucency, thymic hypoplasia, and renal anomalies. The presence of polyhydramnios is predictive of postnatal feeding difficulties.Once the deletion is found, both parents should also undergo cytogenetic analysis.Delivery should occur in a tertiary center.Affected neonates are at risk for seizure disorders due to hypocalcemia.Postnatal problems include speech defects due to palatal abnormalities, repeated infections due to immunodeficiency, developmental delay, feeding issues, and serious behavioral and psychiatric problems.22q11.2 deletion is inherited as an autosomal dominant trait.The major causative gene is TBX1, a member of the T-box protein family of genes.