We report a case of a 34-year-old male with severe multisystemic involvement (including the testis, musculoskeletal system, skin, upper respiratory tract, ocular system, peripheral nerves, abdomen, and kidney) due to granulomatosis with polyangiitis (GPA) and a high proteinase 3 (PR3)-antineutrophil cytoplasmic antibodies (PR3ANCA) titer. This evidence concerns the gene PRTN3 and granulomatosis with polyangiitis.