Pathophysiology: The Case Study of Robert’s 22q11.2 Deletion Syndrome

Posted: June 6th, 2021

Pathophysiology: The Case Study of Robert’s 22q11.2 Deletion Syndrome

Robert, an 11-year-old boy, has been undergoing regular medical examinations and monitoring due to complications arising from a genetic condition. He has been diagnosed with 22q11.2 deletion syndrome, a disorder caused by a microdeletion of genetic material on chromosome 22. Individuals with this syndrome exhibit a wide range of clinical manifestations and developmental issues across multiple organ systems. This paper will analyze the pathophysiology underlying Robert’s condition based on current scientific understanding.
Clinical Presentation

22q11.2 deletion syndrome commonly presents with congenital cardiac abnormalities, distinctive facial features, recurrent infections, and developmental delays (Sullivan, 2019). Robert has experienced some of these classic symptoms, including attention deficit hyperactivity issues and increased susceptibility to kidney problems as per his medical history (Kraus et al., 2018). The syndrome’s variable clinical expression means symptoms can differ greatly even between family members (Sullivan, 2019). While the exact manifestations Robert experiences are unknown, common issues associated with 22q11.2 deletion syndrome will be discussed.
Genetic Basis
22q11.2 deletion syndrome results from a microdeletion on the long (q) arm of chromosome 22 within the 11.2 band (Sullivan, 2019). Through advanced genetic screening techniques, Robert’s condition was identified to be caused by a deletion within this specific region (Kraus et al., 2018). The deleted segment contains around 30-50 genes, and disrupting this gene dosage leads to the syndrome’s wide-ranging effects (Sullivan, 2019). While the clinical features are heterogeneous, understanding how disruption of key genes contributes to pathophysiological changes provides insight into Robert’s condition.
Immune System Abnormalities
One of the most prominent effects of 22q11.2 deletion syndrome involves the immune system. Around 90% of individuals experience hypoplasia or aplasia of the thymus gland, which plays a crucial role in T-cell maturation and immune function (Sullivan, 2019). This thymic abnormality impairs the development and activity of T-lymphocytes, weakening cell-mediated immunity (Antshel & Shi, 2016). The resulting immune deficiency predisposes to recurrent infections, consistent with Robert’s medical history. Genes like TBX1 that are deleted regulate thymus organogenesis, and their absence disrupts normal immune development (Sullivan, 2019).
Congenital Heart Defects
Cardiovascular anomalies are also very common in 22q11.2 deletion syndrome, occurring in approximately 75% of cases (Sullivan, 2019). Robert may be at heightened risk, though no specific cardiac issues were noted. The microdeletion involves genes important for heart morphogenesis, including transcription factors that regulate outflow tract septation (Sullivan, 2019). Their disruption can lead to conotruncal abnormalities like tetralogy of Fallot, interrupted aortic arch, and ventricular septal defects (Antshel & Shi, 2016). Further examination may be needed to rule out any underlying cardiac pathologies in Robert’s case.
Neurodevelopmental and Psychiatric Issues
Individuals with 22q11.2 deletion syndrome have an elevated chance of neurodevelopmental delays, cognitive impairments, autism spectrum disorder, and psychiatric illnesses (Antshel & Shi, 2016). In Robert, attention deficit issues have already emerged (Kraus et al., 2018). The deleted region contains genes involved in forebrain development and neuronal migration, and their haploinsufficiency may disrupt processes like synaptogenesis and pruning (Antshel & Shi, 2016). This could account for the high rates of learning disabilities and neuropsychiatric conditions associated with the syndrome. Robert may benefit from developmental monitoring and early intervention.
Conclusion
In summary, Robert’s 22q11.2 deletion syndrome results from a microdeletion on chromosome 22 disrupting around 30-50 genes. This genetic abnormality leads to diverse pathophysiological consequences by interfering with processes like immune organogenesis, heart morphogenesis, and neurodevelopment. Understanding how disruption of key genes contributes to the clinical manifestations provides insight into Robert’s condition and highlights areas that require ongoing medical management and surveillance. With a multidisciplinary care approach targeting the various systems involved, optimal treatment outcomes may be achieved.
References
Antshel, K. M., & Shi, F. (2016). Genetic syndromes associated with intellectual disability. Child and adolescent psychiatric clinics of North America, 25(2), 339–357. https://doi.org/10.1016/j.chc.2015.12.002
Kraus, C., Höhne, J., Ritter, C. A., Schweiger, B., Ropers, H. H., & Caliebe, A. (2018). 22q11.2 deletion syndrome: an update. European journal of human genetics : EJHG, 26(2), 149–161. https://doi.org/10.1038/s41431-017-0064-5
Oskarsdóttir, S., Vujic, M., & Fasth, A. (2017). Incidence and Prevalence of the 22q11.2 Deletion Syndrome: A Population-Based Study in Western Sweden. Birth defects research, 109(15), 1225–1229. https://doi.org/10.1002/bdr2.1113
Sullivan, K. E. (2019). Clinical and diagnostic issues in 22q11.2 deletion syndrome. Genetics in medicine : official journal of the American College of Medical Genetics, 21(1), 11–21. https://doi.org/10.1038/s41436-018-0028-x

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Pathophysiology: The Case Study Essay Initial Post

Robert, who is 11 years old, undergoes regular examinations and is observed by medical specialists from an early age. He is experiencing complications provoked by an illness described as major issues connected with his chromosomes’ condition. This sickness is believed to be a genetic disease characterized by a microdeletion on chromosomal 22’s long arm (Kraus et al., 2018). Autism spectrum syndrome and attention deficit hyperactivity issues are more prevalent among children with this disease. Kidney difficulties, schizophrenia, hearing problems, and inflammatory illnesses, including rheumatoid arthritis, are linked to this condition. Multiple later-onset illnesses, such as autoimmune disease, overweight, and mental disorder, are more probable to appear in individuals.

Congenital cardiac abnormalities, unique facial traits, recurrent infections, developmental disorders, learning challenges, and birth defects are these illness’s common symptoms. The symptoms of this illness differ tremendously, even within family members, and it impacts many different regions of the body (Sullivan, 2019). Other congenital problems that affected people may have as neonates include renal anomalies and substantial feeding complications. Gastrointestinal discomfort is also fairly frequent in this patient group and clinical setting. Genetic screening is considered the method that serves as a marker of the diagnosis, which is predicted based on the clinical symptoms due to the substantial number of clinical manifestations and the range of appearances. It is suspected in individuals who exhibit one or more chromosomal deletion indications. Inadequate penetrance is a feature of this disease; as a result, numerous variations can occur in clinical expression between people.