In a study comparing IO (defined by serum ferritin >1500 ng/mL or LIC >7 mg/g) in transfusion-dependent patients with DBA, SCD or beta-thalassemia, the levels of NTBI were higher in DBA than in both beta-thalassemia and SCD (2.50 μmol/L versus 1.68 and −0.23, respectively) [108] The levels of sTfR were undetectable in DBA patients, illustrating the decreased erythroblast maturation, and hepcidin levels were appropriately elevated. This evidence concerns the gene TFRC and Schnyder corneal dystrophy.