X-Linked Agammaglobulinemia
(XLA) LA is an inherited immune disorder caused by an inability to produce B cells or the immunoglobulins (antibodies) that the B cells make. The mutated gene responsible for XLA (Bruton tyrosine kinase or BTK) is located on the X chromosome. XLA is also called Bruton type agammaglobulinemia, X-linked infantile agammaglobulinemia, and congenital agammaglobulinemia.
Causes
XLA is caused by mutations in the BTK gene found on the X chromosome. This gene normally produces a protein that is required for the development of B cells. XLA is an X-linked recessive disease. Because males only have one X chromosome, they are affected if they inherit an X chromosome containing mutated BTK.
Symptoms & Diagnosis
Infants with XLA develop frequent infections of the ears, throat, lungs, and sinuses. Serious infections also can develop in the bloodstream, central nervous system, skin, and internal organs. People with XLA have extremely low numbers of B cells, and blood tests will show extremely low levels of all types of immunoglobulins (antibodies).
