[Primary immunodeficiencies and Bruton's disease genetic analysis: which prospects offers this genetic diagnosis?]

Bruton's disease is the most frequently primary X-linked immunodeficiency. Bruton's tyrosine kinase (Btk) is encoded by the XLA gene that when mutated causes bruton's disease. This protein acts in multiple intracellular signaling pathways where the BCR (B-cell receptor) pathway is the most elucidated. Moreover 400 mutations were found and identified as responsible for B-cells differentiation block; consequences are a lack of B-cells in peripheral blood and hypo/agammaglobulinemia. Thus, patients are more susceptible to early and recurring infections occurring before the age of one year. Laboratory testing allow differential diagnosis among primary immunodeficiencies in which others hypogammaglobulinemia. Genetic analyses help physicians for clinical and biological diagnosis, and allow prenatal diagnosis for patient's family. Patient's management is based upon polyclonal immunoglobulin supplementation, infectious diseases prevention and genetic advice.