Acquired Pure Red Cell Aplastic in one of the Monozygotic Twins with Common Variable Immunodeficiency

Abstract BackgroundCommon variable immunodeficiency (CVID) is the most prevalent primary immune defects in adults. It has become clear that most cases of CVID have a polygenic rather than a monogenic inheritance. CVID patients are prone to recurrent infection, and an increased incidence of certain autoimmune and neoplastic disorders. Monozygotic twins share identical genetic basis and may serve as a powerful model for study on genetic defects.Case presentationHere, we report a case of monozygotic twins were diagnosed with CVID at their 30s’. They featured a partly similar profile of clinical manifestations, including severe, recurring infections and bone pain. Interestingly, only the elder brother developed pure red cell aplastic (PRCA), and relieved after 5-month’s treatment with 100 mg/d of cyclosporine treatment. Whole-exome sequencing (WES) was utilized to investigate genetic defects.ConclusionsThe results suggest that a combination effect of deleterious variations maybe the cause, such as VDR, NHEJ1, DOCK5, NOD2 and C3, which were predicted by bioinformatics analysis. The potential combinatorial effects in CVID is inferred from their roles in T and B cell signal pathways activation.