The patient was diagnosed with PJI according to the 2018 ICM diagnostic criteria, which specify that normally the patient's white blood cell count (WBC) ranges from 3.5 × 108/L to 10 × 108/L, the neutrophil percentage (PMN) from 0.5 to 0.7, C-reactive protein (CRP) from 0–0.8 mg/dL, interleukin-6 (IL-6) from 0 to 5.9 pg/mL, the erythrocyte sedimentation rate (ESR) from 0 to 20 mm/h, the plasma D-dimer from 0 to 0.55 μg/mL. The gene discussed is CRP; the disease is juvenile polyposis syndrome.