X-linked agammaglobulinemia (a-gam-uh-glob-u-lih-NEE-me-uh) — or XLA — is an inherited (genetic) immune system disorder that reduces your ability to fight infections. People with XLA may experience infections of the inner ear, sinuses, respiratory tract, bloodstream and internal organs.
XLA affects males almost exclusively, although females can be genetic carriers of the condition. Most people with XLA are diagnosed in infancy or early childhood, once it's clear that they are experiencing repeated infections. Sometimes, people are not diagnosed until adulthood.