- DiGeorge Syndrome is a congenital immunodeficiency due to defects in the T lymphocytes development caused by aplasia/hypoplasia of the thymus.
- Synonyms: 22q11 Microdeletion syndrome, 22q11.2 deletion syndrome, CATCH-22 (CATCH 22) syndrome, Velocardiofacial syndrome & Congenital thymus aplasia
- ICD: 10-CM D82.1
- Epidemiology:
- Incidence: 1 per 4000 to 1 per 7000 births.
- Prevalence: True prevalence can only be determined by uniform newborn screening.
- Course: can be severe/life long or subside after few months in the neonate
- Etiology:
- In most of the cases→ New mutation→ Microdeletion of 22q11 (MC microdeletion syndrome in humans)
- In 7% of cases AD inheritance from parents (parents with 22q11.2 deletion have a 50% risk of transmitting the deletion)
- Pathogenesis: Microdeletion of 22q11 (22q11.2)→Maldevelopment of the 3rd and 4th pharyngeal arches and their associated pharyngeal pouches.→ hypoplasia of parathyroid glands and thymus, Facial Dysmorphism and Congenital Heart Defects.
- Presentation (with varying severity) :
1. Primary Cellular immunodeficiency |
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2. Hypocalcemia |
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3. Cardiac & Vascular malformations |
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4. Facial Dysmorphism |
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- Acronym CATCH-22 (CATCH 22) after Joseph Heller’s Novel
- C ardiac abnormality
- A bnormal facies
- T hymic aplasia
- C left palate
- H ypocalcemia / hyperparathyroidism
- Acronym CATCH-22 (CATCH 22) after Joseph Heller’s Novel
- Dx:
- Age of Dx: Severe cases with serious congenital cardiac defects or hypocalcemia are likely to be diagnosed in the neonatal period & mild cases with defects like submucous cleft palate or minimal facial anomalies are diagnosed later in childhood.
- CBC: low and T-cell count
- Other immuno-Dx: lymphocyte phenotyping & Lymphocyte proliferation testing
- Serum calcium
- Echocardiogram: CVS malformation
- Genetic testsing:2 status
- Therapy (based on its severity):
- Infections: antibiotics and antimycotics
- Hypocalcemia: Cholecalciferol
- Severe immunodeficiency: Bone Marrow transplant & Thymus transplant (optional) to establish functioning immune cells
- Severe CVS & facial defects: surgery
Also read:
- Webs:
- The literature on DiGeorge Syndrome: Link
- Research papers on DiGeorge Syndrome: PubMed & GoogleScholar
Also Watch:
- DiGeorge Syndrome from the Youtube channel “Osmosis”
- DiGeorge Syndrome from the Youtube channel “Pixorize”
- DiGeorge Syndrome from the Youtube channel “Armando Hasudungan”
- DiGeorge Syndrome from the Youtube channel “NationwideChildrens”
References:
- DiGeorge syndrome, Hamada H, Terai M. Nihon Rinsho. 2006 Jun 28;Suppl 2:46-8. Japanese.
- 22q11.2 deletion syndrome, shikawa T. Nihon Rinsho. 2006 Jun 28;Suppl 2:70-3.
- CATCH 22. Matsuo N, Yamagishi H. Ryoikibetsu Shokogun Shirizu. 2000;(30 Pt 5):150-3.
- Chromosome 22q11.2 deletion syndrome: DiGeorge syndrome/velocardiofacial Syndrome. Sullivan KE. Immunol Allergy Clin North Am. 2008 May;28(2):353-66.
- Transient neonatal hypocalcemia. Onset Manifestation of the 22q11.2 deletion syndrome. Pusceddu M, Bertone A, Campra D, Pontoriero D, Guala A. Minerva Pediatr. 2002 Aug;54(4):343-5.
- DiGeorge anomaly in the absence of chromosome 22q11.2 deletion. Rope AF, Cragun DL, Saal HM, Hopkin RJ. J Pediatr. 2009 Oct;155(4):560-5.