Agammaglobulinemia is an inherited disorder characterized by very low levels of protective immunoglobulins. Persons with this disorder develop repeated infections.

Agammaglobulinemia is rare disorder that primarily affects males, because it is inherited as an X-linked recessive trait (like hemophilia). It is the result of a genetic abnormality that blocks the development of normal, mature B-lymphocyte cells. As a consequence, the body produces very little (if any) gamma globulin (IgG) and other immunoglobulins in the bloodstream. Immunoglobulins are molecules that play a significant role in the immune response, which protects against illness and infection.

In the absence of protective immunoglobulins, affected individuals develop repeated infections. People with this disorder are particularly susceptible to bacterial infections caused by Haemophilus influenzae, pneumococcus (Streptococcus pneumoniae), and staphylococci as well as repeated viral infections. The upper respiratory tract, lungs, and skin are common sites of infection.

The person may have a family history of agammaglobulinemia (or other immune disorder).

Symptoms include frequent episodes of:

• Sinusitis
• Conjunctivitis
• Pneumonia
• Bronchitis
• Other respiratory infections
• Skin infections
• Chronic diarrhea

Infections typically appear in the first 4 years of life.

The disorder is confirmed by laboratory measurement of serum immunoglobulins. Tests include:

• Immunoelectrophoresis - serum
• Quantitative immunoglobulins (nephelometry)
• IgG usually less than 200 mg/dL
• IgA and IgM almost unmeasurable
• Flow cytometry to measure circulating B lymphocytes