HAMP and Schnyder corneal dystrophy: [20] In American adults, serum hepcidin in heavily transfused SCD patients had a similar degree of correlation with serum ferritin but a larger negative correlation with EPO (r2 = −0·34, p-0·03), which in our dataset, did not reach statistical significance – possibly due to the extremes of hemoglobin concentration resulting from our study design.