Thelansis

  DiGeorge syndrome (DGS) is a congenital disorder with a broad phenotypic presentation caused primarily by a microdeletion of chromosome 22 at 22q11.2. This mutation fails in the proper development of the pharyngeal pouches, which are responsible for the embryologic development of the middle and external ear, maxilla, palatine tonsils, mandible, thyroid, parathyroids, thymus, aortic arch, and cardiac outflow tract. DGS symptoms include cardiac anomalies, recurrent infections, abnormal facies, thymic hypoplasia or aplasia, cleft palate, developmental delay, and hypocalcemia. DGS symptoms include a thymus that is absent or hypoplastic, cardiac abnormalities, hypocalcemia, and parathyroid hypoplasia. The absence of thymic tissue, the organ responsible for T lymphocyte development, is the most concerning feature of DGS. A complete lack of the thymus, which is extremely rare and affects less than 1% of DGS patients, is associated with severe combined immunodeficiency (SCID). T-cells ...