DiGeorge syndrome (22q11.2 deletion syndrome, or 22q11.2DS) is the most common microdeletion syndrome with an estimated minimum prevalence of 1.02 to 4.7 per 10,000 live births.[1]McDonald-McGinn DM, Sullivan KE, Marino B, et al. 22q11.2 deletion syndrome. Nat Rev Dis Primers. 2015 Nov 19;1:15071.
https://pmc.ncbi.nlm.nih.gov/articles/PMC4900471
http://www.ncbi.nlm.nih.gov/pubmed/27189754?tool=bestpractice.com
[11]Blagojevic C, Heung T, Theriault M, et al. Estimate of the contemporary live-birth prevalence of recurrent 22q11.2 deletions: a cross-sectional analysis from population-based newborn screening. CMAJ Open. 2021 Jul-Sep;9(3):E802-9.
https://pmc.ncbi.nlm.nih.gov/articles/PMC8373039
http://www.ncbi.nlm.nih.gov/pubmed/34404688?tool=bestpractice.com
[12]Panamonta V, Wichajarn K, Chaikitpinyo A, et al. Birth prevalence of chromosome 22q11.2 deletion syndrome: a systematic review of population-based studies. J Med Assoc Thai. 2016 Aug;99 Suppl 5:S187-93.
http://www.ncbi.nlm.nih.gov/pubmed/29906080?tool=bestpractice.com
Evidence from the Western Götaland region of Sweden shows the mean annual incidence is approximately 14 per 100,000 live births (approximately 23 per 100,000 live births in Gothenburg, where a multidisciplinary specialist team is based), and the prevalence is approximately 13 per 100,000 children below 16 years of age (approximately 23 per 100,000 in Gothenburg).[13]Oskarsdottir S, Vujic M, Fasth A. Incidence and prevalence of the 22q11 deletion syndrome: a population-based study in Western Sweden. Arch Dis Child. 2004;89:148-51.
https://pmc.ncbi.nlm.nih.gov/articles/PMC1719787
http://www.ncbi.nlm.nih.gov/pubmed/14736631?tool=bestpractice.com
Evidence from North and South America shows that males and females are equally affected, and there is no demonstrated ethnic predisposition, although it may influence the specific manifestations of the disorder.[14]Botto LD, May K, Fernhoff PM, et al. A population-based study of the 22q11.2 deletion: phenotype, incidence, and contribution to major birth defects in the population. Pediatrics. 2003;112:101-7.
http://www.ncbi.nlm.nih.gov/pubmed/12837874?tool=bestpractice.com
[15]Munoz S, Garay F, Flores I, et al. Clinical heterogeneity of the chromosome 22q11 microdeletion syndrome. Rev Med Chil. 2001;129:515-521.
http://www.ncbi.nlm.nih.gov/pubmed/11464533?tool=bestpractice.com
Most 22q11.2 deletions presenting with cardiac disease or hypocalcaemia are detected in infancy. Patients who do not have such overt manifestations may be easily overlooked, and the syndrome may be diagnosed later because of learning disabilities, palatal insufficiency, or psychiatric disease. The disorder was previously thought to be rare in adults, but with improved survival after cardiac surgery and more widespread use of fluorescence in situ hybridisation testing for the deletion, more adults are being identified.[16]Boot E, Óskarsdóttir S, Loo JCY, et al. Updated clinical practice recommendations for managing adults with 22q11.2 deletion syndrome. Genet Med. 2023 Mar;25(3):100344.
https://www.gimjournal.org/article/S1098-3600(22)01028-0/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/36729052?tool=bestpractice.com
Complete DiGeorge syndrome requiring immune reconstitution through thymic transplant or adoptive transfer of mature T cells is rare, as is the atypical form of the syndrome (complete syndrome with proliferating autoreactive oligoclonal T-cell populations).[6]Markert ML, Alexieff MJ, Li J, et al. Complete DiGeorge syndrome: development of rash, lymphadenopathy, and oligoclonal T cells in 5 cases. J Allergy Clin Immunol. 2004;113:734-741.
http://www.ncbi.nlm.nih.gov/pubmed/15100681?tool=bestpractice.com
[17]Land MH, Garcia-Lloret MI, Borzy MS, et al. Long-term results of bone marrow transplantation in complete DiGeorge syndrome. J Allergy Clin Immunol. 2007;120:908-15.
http://www.ncbi.nlm.nih.gov/pubmed/17931564?tool=bestpractice.com