[Validation of a Bruton's disease genetic analysis method].

Bruton's disease is the most frequently primary X-linked immunodeficiency. Patients are more susceptible to early and recurring infections associated with hypo/agammaglobulinemia and a severe B-cell deficiency. Moreover, 400 mutations were found in the XLA gene which codes the Btk tyrosine kinase and were identified as responsible for Bruton's disease. Genetic study was carried out with one group of patients named NECKER, composed by five XLA patients and two parents whose XLA gene was sequenced by an Italian crew. Results were obtained by PCR of 19 exons and initial/terminal intron's parts, followed by PCR-sequencing with universal primers and sequencing. The results from this study allowed the validation of the sequencing technique by comparing NECKER group data (equivalent results with Italian data). In addition, the mutation multiplicity (described or not, coding/non coding) need an exact analysis that should be given to clinicians through clear and trustful results. In this way, a strategy to analyse untreated results was created based on the mutation type. The genetic analysis could help physicians for uncertain diagnosis in immune defficiencies, allows proposing a genetic advice to the patient's family and the construction of a data base permits a best understanding of this disease.