label: X-Linked Agammaglobulinemia
label_lc: x-linked agammaglobulinemia
description: "X-linked agammaglobulinemia.  An immunodeficiency state characterized (usually) by profoundly low concentrations of serum immunoglobulins of all classes, although occasionally significant amounts of one or more isotypes can be found.  The fundamental defect in XLA affects early lineage B cells."