The diagnosis of GPA was achieved due to systemic pulmonary, ENT and renal involvement, the positivity of anti-neutrophil cytoplasmic antibody directed against proteinase 3 (C-ANCA) and bronchial and nasal biopsies showing granulomatous inflammation with a dense perivascular infiltrate destroying the vessel wall. This evidence concerns the gene PRTN3 and granulomatosis with polyangiitis.