A 13-year-old male with global developmental delay and epilepsy secondary to Lennox Gastaut syndrome presented to his local general pediatrics service in March 2022 with a bilateral lower limb purpuric rash, arthritis, severe anemia (Hb=5.9g/dl), normal platelets (368x109/L), elevated C reactive protein (CRP=80mg/L) and elevated serum IgA (5.6 g/L range 0.5-3.5g/L) (Table 1). This evidence concerns the gene CRP and arthritic joint disease.