Infants with X-linked agammaglobulinemia start having recurring coughs and/or infections of the nose, ears, skin, sinuses, and lungs at about age 6 months.
Doctors diagnose the disorder by measuring immunoglobulin levels and the number of B cells.
Immune globulin is given throughout life, and antibiotics may be given continuously.
(See also Overview of Immunodeficiency Disorders.)
X-linked agammaglobulinemia results from a mutation in a gene on the X (sex) chromosome (called an X-linked disorder). X-linked disorders usually affect boys.
For about the first 6 months after birth, immunoglobulins from the mother protect against infection. At about age 6 months, levels of these immunoglobulins start to decrease, and affected infants start having recurring cough, nasal infections (rhinitis), and/or infections of the ears, skin, sinuses, and lungs. The infections are usually due to bacteria such as pneumococci, streptococci, and Haemophilus bacteria. Some unusual viral infections of the brain may develop. The tonsils are very small, and lymph nodes do not develop.
X-linked agammaglobulinemia increases the risk of developing infections in the joints (infectious arthritis), irreversible widening due to chronic inflammation of the airways (bronchiectasis), and certain cancers.
With early diagnosis and treatment, life span is often unaffected, unless brain infections develop.
Blood tests are done to measure immunoglobulin levels and the number of B cells.
Genetic testing may be done to confirm the diagnosis of X-linked agammaglobulinemia but is not usually needed. Testing is recommended for close relatives.
Prenatal genetic screening is recommended for people if a mutation that causes X-linked agammaglobulinemia has been identified in their family.
Immune globulin (antibodies obtained from the blood of people with a normal immune system) is given throughout life to provide the missing antibodies and thus help prevent infections. Immune globulin may be injected into a vein (intravenously) or under the skin (subcutaneously).
Antibiotics are promptly given to treat bacterial infections and may be given continuously.
People with X-linked agammaglobulinemia are not given vaccines that contain live but weakened organisms (viruses or bacteria). These vaccines include rotavirus vaccines, measles-mumps-rubella vaccine, chickenpox (varicella) vaccine, one type of varicella-zoster (shingles) vaccine, bacille Calmette-Guérin (BCG) vaccine, and influenza vaccine given as a nasal spray.
Despite these measures, chronic sinus and lung infections often develop.