Agammaglobulinemia, X-Linked

Alternative Names

  • XLA
  • Bruton-Type Agammaglobulinemia
  • Agammaglobulinemia, X-Linked, Type 1
  • AGMX1
  • Immunodeficiency 1
  • IMD1
  • Hypogammaglobulinemia, X-Linked
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WHO-ICD-10 version:2010

Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism

Certain disorders involving the immune mechanism

OMIM Number


Mode of Inheritance

X-linked recessive

Gene Map Locus



X-linked agammaglobulinemia (XLA) is a rare immune disorder characterized by a complete deficiency of B lymphocytes. In the absence of normal mature B cells, affected patients have impaired immunity and are susceptible to infections and illnesses, particularly in the first two years of life, which can sometimes be fatal. Some of the common infections are otitis media, conjunctivitis, sinopulmonary infections, diarrhea, and skin infections. Viral infections are rare, although enetroviral infections may be seen. The disease almost exclusively affects males. Worldwide, less than 1 in 200,000 neonates are affected with this condition.

A diagnosis of XLA is suspected in male infants with recurrent bacterial infections, reduction in all classes of serum immunoglobulins, and a total absence of B lymphocytes. Confirmation of the diagnosis requires mutation analysis of the BTK gene. Treatment involves regular injections or infusions of gamma-globulins. Simultaneously, aggressive use of antibiotics may be required to combat chronic sinusitis and pulmonary disease.

Molecular Genetics

XLA is caused by mutations in the BTK (Bruton Tyrosine Kinase) gene. This gene, located on the X-chromosome, codes for a tyrosine kinase that plays an essential role in the development, differentiation and signaling of B lymphocytes. XLA is, therefore, transmitted in an X-linked recessive manner. The BTK gene is a 36Kb long stretch of DNA. The protein functions as a non-receptor tyrosine kinase.

Epidemiology in the Arab World

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Other Reports


Mullick (1990) described a case of XLA in Kuwait. No further details about the case could be accessed.

[Mullick P. The spectrum of X-linked agammaglobulinemia. Kuwait Med J. 1990; 24(1):84-8.]

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