B Cell Disorders in Children—Part I

Purpose of Review: The advent of enhanced genetic testing has allowed for the discovery of gene defects underlying two broad categories of antibody deficiency in children: agammaglobulinemia and common variable immunodeficiency (CVID). This review describes the underlying gene defects and the clinical manifestations. Recent Findings: Because novel monogenetic defects have been discovered in both categories, a strict dichotomous classification of B cell disorders as either X-linked agammaglobulinemia or common variable immunodeficiency is no longer appropriate. Summary: Advances in genetic testing technology and the decreasing cost of such testing permit more precise diagnosis of B cell disorders, more helpful information for genetic counselors, and a better understanding of the complex process of B cell development and function. More disorders await discovery.