DiGeorge Syndrome Precision Panel
DiGeorge Syndrome (DGS) is one of a group of phenotypically similar disorders including velocardiofacial syndrome (VCFS) and conotruncal anomaly face (CTAF).
Overview
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DiGeorge Syndrome (DGS) is one of a group of phenotypically similar disorders including velocardiofacial syndrome (VCFS) and conotruncal anomaly face (CTAF). These disorders share a microdeletion of chromosome 22q11.2, a region known as the DiGeorge critical region. Since there are overlapping phenotypic features between these syndromes, they have been designated as 22q11.2 deletion syndromes. It is one of the most common chromosomal microdeletion disorders. The 22q11.2 deletion results in a range of embryonic developmental disruptions involving the head, nek, brain, skeleton, and kidneys. There is also a defect in T cell production which in turn increases susceptibility for infections as well autoimmunity. Neuropsychiatric manifestations of these disorders cause moderate/severe impairment of functionality in these patients. The prognosis for these disorders is highly variable, depending on the nature and degree of involvement of different organs.
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The Igenomix DiGeorge Syndrome Precision Panel can serve as a directed and accurate diagnostic tool ultimately leading to a better management and prognosis of the disease. It provides a comprehensive analysis of the genes involved in this disease using next-generation sequencing (NGS) to fully understand the spectrum of relevant genes.
Indication
- The Igenomix DiGeorge Syndrome Precision Panel is indicated in those cases where there is a clinical suspicion or diagnosis with or without the following manifestations:
- Retrognathia or micrognathia
- Long face
- High and broad nasal bridge
- Narrow palpebral fissures
- Small teeth
- Short philtrum
- Low-set, malformed ears
- Congenital heart defects
- Hypocalcemia
- Cognitive, behavioral and psychiatric problems
- Increased susceptibility to infections
Clinical Utility
The clinical utility of this panel is:
- The genetic and molecular diagnosis for an accurate clinical diagnosis and improve prognosis.
- Early initiation of treatment with a multidisciplinary approach involving pediatrics, general medicine, surgery, psychiatry, psychology, interventional therapies (physical, occupational, speech, language and behavioral).
- Start early medical care with calcium supplementation, surgical care and bone marrow transplantation for profound immunodeficiency, early surveillance and prevention of complications.
- Risk assessment and genetic counselling of asymptomatic family members to identify the individuals at risk.
- Improvement of delineation of genotype-phenotype correlation.
References
Butts SC. The facial phenotype of the velo-cardio-facial syndrome. Int J Pediatr Otorhinolaryngol. 2009 Mar. 73(3):343-50
McDonald-McGinn, D. M., & Sullivan, K. E. (2011). Chromosome 22q11.2 deletion syndrome (DiGeorge syndrome/velocardiofacial syndrome). Medicine, 90(1), 1–18. https://doi.org/10.1097/MD.0b013e3182060469
McDonald-McGinn, D. M., Sullivan, K. E., Marino, B., Philip, N., Swillen, A., Vorstman, J. A., Zackai, E. H., Emanuel, B. S., Vermeesch, J. R., Morrow, B. E., Scambler, P. J., & Bassett, A. S. (2015). 22q11.2 deletion syndrome. Nature reviews. Disease primers, 1, 15071. https://doi.org/10.1038/nrdp.2015.71
Kuo, C. Y., Signer, R., & Saitta, S. C. (2018). Immune and Genetic Features of the Chromosome 22q11.2 Deletion (DiGeorge Syndrome). Current allergy and asthma reports, 18(12), 75. https://doi.org/10.1007/s11882-018-0823-5
Morrow, B. E., McDonald-McGinn, D. M., Emanuel, B. S., Vermeesch, J. R., & Scambler, P. J. (2018). Molecular genetics of 22q11.2 deletion syndrome. American journal of medical genetics. Part A, 176(10), 2070–2081. https://doi.org/10.1002/ajmg.a.40504
Fung, W. L., Butcher, N. J., Costain, G., Andrade, D. M., Boot, E., Chow, E. W., Chung, B., Cytrynbaum, C., Faghfoury, H., Fishman, L., García-Miñaúr, S., George, S., Lang, A. E., Repetto, G., Shugar, A., Silversides, C., Swillen, A., van Amelsvoort, T., McDonald-McGinn, D. M., & Bassett, A. S. (2015). Practical guidelines for managing adults with 22q11.2 deletion syndrome. Genetics in medicine : official journal of the American College of Medical Genetics, 17(8), 599–609. https://doi.org/10.1038/gim.2014.175