Risk factors of clinical dysimmune manifestations in children with 22q11.2 deletion syndrome

chromosome 22

Risk factors of clinical dysimmune manifestations in a cohort of 86 children with 22q11.2 deletion syndrome: A retrospective study in France

22q11.2 deletion syndrome is one of the most common microdeletion syndromes. Patients with this syndrome have a higher risk of infections, autoimmune diseases, and allergies. Deletions that include the TBX1 gene lead to impaired thymus development and lymphopenia. This article looks at the relationship between these immunological impairments and the immunological profile of children with 22q11.2 deletion syndrome.

Of the 86 children in the retrospective study, clinical manifestations prior to age 18 include severe infections (34%), autoimmune diseases (13%), and allergic episodes (27%). These clinical manifestations are associated with decreased T-cells (59% of patients), and immunoglobulin deficiencies, particularly IgA and IgM deficiency. Immunoglobulin G deficiencies were not found in this cohort.

The study found that low level CD4+ T-cells was associated with an increased risk for severe infections. None of the patients had any opportunistic infections, which led the authors to question the recommendation of co-trimoxazole preventive therapy. However a history of severe infection was strongly associated with an increased risk of autoimmune disease. Therefore, clinicians should carefully monitor patients with 22q11.2 deletion with a history of severe infections for autoimmune risk.

Among the 86 children, 19% had asthma, compared to 10% in French children under 15 in 2010. The authors found that low level of CD8+ T-cells were associated with an increase in allergies.

This study shows the immune dysfunctions found in 22q11.2 deletion syndrome patients are interrelated and associated with lymphopenia.

Mahé, P. et al. “Risk Factors of Clinical Dysimmune Manifestations in a Cohort of 86 Children with 22q11.2 Deletion Syndrome: A Retrospective Study in France.” American Journal of Medical Genetics Part A, 2019, vol. 179, pp. 2207–2213.

Articles of the month are chosen from newly published genetic research by CDO geneticist, Dr. Iosif Lurie.  For more information on any article please contact info@chromodisorder.org