RESUMO
Background: The cytosolic protein p47-phox (phagocyte oxidase) is one of the essential components of the superoxide generating system in phagocytes and its defect causes approximately 30 percent of the chronic granulomatous disease (CGD) cases. Aim: Two patients were studied, belonging to the same family, without a consanguinous background, in which deficiency or absence of superoxide generation was found together with recurrent and severe infections in one case and benign infections in the second. Methods: The presence of gp91-, p67- and p47-phox in patients and controls was determined by Western Blot analysis of granulocytes. Sequencing of PCR amplified DNA was performed by an enzimatic method. Results: Western Blot analysis showed normal expression of gp91 and p67 and absence of p47-phox. The molecular genetic study demonstrated a homocygotic dinucleotide GT (GT) deletion at the beginning of exon 2 of the p47-phox gene. The same mutation has been found in European, American and Japanese patients. Conclusions: The molecular characterization of this pathology done for the first time in Chile is important for diagnostic classification, patient prognosis, and adequate genetic advice and a possible future therapy