Syndrome, third and fourth pharyngeal pouch
Also called the DiGeorge syndrome (DGS), this disorder is characterized by (1) low blood calcium levels (hypocalcemia) due to underdevelopment (hypoplasia) of the parathyroid glands which control calcium; (2) underdevelopment (hypoplasia) of the thymus, an organ behind the breastbone in which lymphocytes mature and multiply; and (3) defects of the heart involving the outflow tracts from the heart. Most cases of DGS are due to a microdeletion in chromosome band 22q11.2. A small number of cases have defects in other chromosomes, notably 10p13. Named after the American pediatric endocrinologist Angelo DiGeorge. Another name for DGS is hypoplasia of the thymus and parathyroids. According to a report in the October 14th, 1999 issue of The New England Journal of Medicine, transplantation of thymus tissue can restore normal immune function in infants with complete DiGeorge syndrome. Thymus tissue discarded from infants undergoing heart surgery (the thymus becomes disposable with time) was cultured and transplanted into 5 patients with profound immunodeficiency caused by DiGeorge syndrome. Four of the 5 patients then developed T-cell proliferative responses to mitogens (agents that trigger cell division). Early thymus transplantation may thus be useful for patients with DiGeorge syndrome who lack a T-cell system. The thymus transplant promotes successful immune reconstitution. Sources: M. L. Markert and others. Transplantation of Thymus Tissue in Complete DiGeorge Syndrome. N Engl J Med 1999;341:1180-1189. (The original article in the October 14, 1999 issue of The New England Journal of Medicine.) I. L. Weissman and J. A. Shizuru. Immune Reconstitution. N Engl J Med 1999;341:1227-1229. (The accompanying editorial in the October 14, 1999 issue of The New England Journal of Medicine.)

Medical dictionary. 2011.

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  • Third and fourth pharyngeal pouch syndrome — Also called the DiGeorge syndrome (DGS), this disorder is characterized by (1) low blood calcium levels (hypocalcemia) due to underdevelopment (hypoplasia) of the parathyroid glands which control calcium; (2) underdevelopment (hypoplasia) of the… …   Medical dictionary

  • Pharyngeal pouch (embryology) — Infobox Embryology Name = PAGENAME Latin = GraySubject = 13 GrayPage = 65 Caption = Pattern of the branchial arches. I IV branchial arches, 1 4 branchial pouches (inside) and/or pharyngeal grooves (outside) a Tuberculum laterale b Tuberculum… …   Wikipedia

  • syndrome — The aggregate of symptoms and signs associated with any morbid process, and constituting together the picture of the disease. SEE ALSO: disease. [G. s., a running together, tumultuous concourse; (in med.) a concurrence of symptoms, fr. syn,… …   Medical dictionary

  • Syndrome, DiGeorge (DGS) — This congenital disorder is characterized by the convergence of the following three features: {{}}Low blood calcium levels: The low levels of calcium, also known as hypocalcemia, are due to underdevelopment (hypoplasia) of the parathyroid glands… …   Medical dictionary

  • Hypoplasia of the thymus and parathyroids — Also known as the DiGeorge syndrome (DGS), this disorder is characterized by (1) low blood calcium levels (hypocalcemia) due to underdevelopment (hypoplasia) of the parathyroid glands needed to control calcium; (2) underdevelopment (hypoplasia)… …   Medical dictionary

  • Parathyroids, hypoplasia of the thymus and — Also known as the DiGeorge syndrome (DGS), this disorder is characterized by (1) low blood calcium levels (hypocalcemia) due to underdevelopment (hypoplasia) of the parathyroid glands needed to control calcium; (2) underdevelopment (hypoplasia)… …   Medical dictionary

  • Thymus and parathyroids, hypoplasia of — Also known as the DiGeorge syndrome (DGS), this disorder is characterized by (1) low blood calcium levels (hypocalcemia) due to underdevelopment (hypoplasia) of the parathyroid glands needed to control calcium; (2) underdevelopment (hypoplasia)… …   Medical dictionary

  • DGS (DiGeorge syndrome) — This congenital disorder is characterized by the convergence of the following three features: {{}}Low blood calcium levels: The low levels of calcium, also known as hypocalcemia, are due to underdevelopment (hypoplasia) of the parathyroid glands… …   Medical dictionary

  • DiGeorge syndrome (DGS) — This congenital disorder is characterized by the convergence of the following three features: {{}}Low blood calcium levels: The low levels of calcium, also known as hypocalcemia, are due to underdevelopment (hypoplasia) of the parathyroid glands… …   Medical dictionary

  • human embryology — ▪ biology Introduction       the process encompassing the period from the formation of an embryo, through the development of a fetus, to birth.       The human body, like that of most animals, develops from a single cell produced by the union of… …   Universalium

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