Background: Patients with chromosome 18 abnormalities can present with an immune phenotype that resembles common variable immunodeficiency. Knowledge of the genes underlying the immune defects related to chromosome 18 aberrations could improve our understanding of the molecular basis of primary antibody deficiencies. Here we present a patient with ring chromosome 18 affected by primary antibody deficiency and autoimmunity. Methods: Lymphocyte populations were determined by flow cytometry. Specific antibody response to protein vaccines and pneumococcal capsule antigen were measured by ELISA. Genome sequencing was performed using a PCR-free protocol. Case: The patient was diagnosed with ring chromosome 18 for delayed growth and dysmorphic features at the age of 1 month. Array comparative genomic hybridization showed deletions of 18p11.21-pter and 18q21.31-qter. At the age of 10 months, she started having recurrent episodes of otitis media and pneumonia, as well as autoimmune arthritis. Serum immunoglobulins and specific antibody levels were low. The CD19+CD27+ memory B cell and CD45RO+ T cell populations were decreased. Recurrent infections were controlled with parenteral immunoglobulin and autoimmune arthritis was treated with systemic and intra-articular therapies. Conclusions: Selective IgA deficiency is the most common form of immunodeficiency associated with chromosome 18 abnormalities, however patients with ring chromosome 18 may also be affected by specific antibody deficiency and require immunoglobulin replacement for optimal care. These patients might partially share the same genomic loss as in patients with non-syndromic primary antibody deficiency. Statement of novelty: This report highlights an important teaching point about immune deficiency in a chromosomal anomaly that is not infrequently encountered in pediatric hospitals. Furthermore, our investigations provide more insight into the pathogenesis of immunodeficiency among patients with chromosome 18 abnormalities.
In the article "Genome and RNA sequencing in patients with methylmalonic aciduria of unknown cause" by Abrado LS et al (Genet Med 2020;22:432-436), there was an error in Table 1. The Patient ID of the last patient in Table 1 should read WG3023, not WG3123.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.