Patients with the abovementioned symptoms; familial history of XLA
X-linked Agammaglobulinemia, XLA - BTK
Bruton disease
Clinical Features
X-linked agammaglobulinemia (XLA) is an immune deficiency disease. The responsible gene, Bruton's Tyrosinkinase (BTK) gene, codes for an enzyme that plays an important role in the development of B cell differentiation. Disrupted B cell maturation and the corresponding decreased production of antibodies leads to recurrent bacterial infections in affected patients, mainly in the respiratory and digestive tracts.
Due to X chromosomal inheritance, affected patients are almost exclusively men. Women with a mutated allele do not normally fall ill to the disease but may, however, pass this allele on to their male children.
A differentiated analysis of peripheral blood cells normally show a B cell ratio of less than 1%
Genetic Information
X-linked Agammaglobulinemia (XLA) is an X-chromosomal recessive inheritance caused by mutations in the BTK gene located on the long arm of the X chromosome (Xq22.1). All mutations identified to date are scattered throughout all 18 exons. About 90% of mutations are either point mutations or small deletions and/or insertions.
Prevalence
In males, 3 - 6 : 1 000 000
Diagnostic
Indication
Method
PCR followed by sequencing; deletions and/or duplications or one or more exons are captured using MLPA.
Sample Requirement
2 - 4 ml of EDTA blood
Duration
6 - 8 weeks