What is X-linked agammaglobulinemia?
X-linked agammaglobulinemia is a genetic disorder that affects the immune system. X-linked means that it is caused by a change in a gene on the X chromosome. Agammaglobulinemia means that a person lacks immunoglobulins, or antibodies, in the blood. Antibodies are used by the immune system to fight off bacteria, viruses and other foreign material in the body. Without these antibodies the body cannot fight off infections, particularly bacterial infections.
At birth and for about 1 or 2 months, infants are protected by antibodies they received from their mother during pregnancy. These antibodies cross over the placenta and remain in an infant's system for a couple months after birth. After these maternal antibodies start to disappear, infants may develop recurrent infections, usually between 3 and 18 months of age. The most common infections in infants with X-linked agammaglobulinemia are ear infections, sinus infections, and lung infections like bronchitis and pneumonia. Skin and gastrointestinal infections are also common.
X-linked agammaglobulinemia usually is found in boys. Girls rarely develop symptoms. The disorder is caused by changes in the BTK gene. X-linked agammaglobulinemia is also called Bruton’s agammaglobulinemia.
Conley ME, Howard VC. X-linked Agammaglobulinemia. GeneReviews website. http://www.ncbi.nlm.nih.gov/books/NBK1453/ Accessed May 16, 2016.
X-linked Agammaglobulinemia. Genetic Home Reference website. https://ghr.nlm.nih.gov/condition/x-linked-agammaglobulinemia Accessed June 3, 2016.