Classification of transferrin (Tf) subtypes by isoelectric focusing

Summary A sample of 450 sera from unrelated individuals from Southern Germany was examined by isoelectric focusing on polyacrylamide gels. Three common subtypes, TfC1, C2-1, and C2, were differentiated. In addition, the rare variants TfB1, B1-2, B2, D1, D1-2, D2, and D3 were observed. The frequencies of the Tf alleles in our sample were found to be: Tf^C1=0.8544, Tf^C2=0.1367, Tf^B1=0.0011, Tf^B1-2=0.0022, Tf^B2=0.0045, and Tf^D1=0.0011. Analysis of 73 parents with 73 children did not show deviations from the expected mode of inheritance. Modification of the method by addition of 0.01 M FeCl₃ to the sera prior to examination did, however, reveal further variation and permitted the distinction of six subtypes, C1, C2-1, C2, C3, C3-1, and C3-2.This paper is dedicated to Fritz Hartmann, MD, Professor of Medicine, Hannover Medical School, FRG, on the occasion of his 60th birthday