Expression of the Gene Defect in X-Linked Agammaglobulinemia

Abstract

Although X-linked agammaglobulinemia was one of the first immunodeficiencies described,¹ the genetic defect responsible for this disorder has not yet been identified. X-linked agammaglobulinemia is characterized by the onset of recurrent bacterial infections in the first few years of life. Concentrations of serum immunoglobulins are markedly decreased, and the number of B cells in the peripheral circulation is less than 1 percent of the normal value.^{2 3 4 5} However, approximately normal numbers of preB cells, the noncirculating precursors of B cells, can be detected in the bone marrow of affected persons.⁶ The failure of preB cells to differentiate into B cells may . . .