The scoring coefficients in the canonical plot were as follows: Canonical 1 = 0.90 Log [serum ferritin level, ng/mL]−0.18 Log [days of illness at the onset of arthritis]−0.19 Log [serum MMP-3 level, ng/mL] + 0.19 Log [months of age], Canonical 2 = 0.36 Log [serum ferritin level, ng/mL] + 0.91 Log [days of illness at the onset of arthritis]−0.02 Log [serum MMP-3 level, ng/mL]−0.56 Log [months of age]. This evidence concerns the gene MMP3 and arthritic joint disease.