Background An 11-year-old boy who had hematuria at a routine health check-up was later diagnosed with proteinase 3 (PR3) antineutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis. Despite treatment with corticosteroids and immunosuppressants, he went on to develop end-stage renal disease. The patient received a renal transplant at the age of 16 years, but relapse of PR3-ANCA-related nephritis to the graft occurred three times. Each relapse was successfully treated with corticosteroids and immunosuppressants. An echocardiogram at the age of 19 years revealed moderate-to-severe aortic regurgitation. The patient died of pneumonia when he was 24 years old. Autopsy revealed a perforation in the noncoronary cusp of the aortic valve and recurrence of crescentic glomerulonephritis in the transplanted kidney.Investigations Physical examinations, urine and blood analyses, renal biopsies, echocardiograms and autopsy.Diagnosis PR3-ANCA-associated glomerulonephritis, recurrence of crescentic glomerulonephritis to the graft, aortic regurgitation and perforation in the noncoronary cusp of the aortic valve.Management Immunosuppressants and corticosteroids.