Transferrin (Tf) polymorphism: an analysis by isoelectric focusing.

The polymorphism of the transferrin (Tf) system was studied in a total of 300 unrelated Japanese individuals from Miyagi prefecture, the northern part of Japan using isoelectric focusing in thin-layer polyacrylamide gel. In our population samples three common phenotypes and nine variants were observed. The calculated allele frequencies were TfC1 = 0.773, TfC2 = 0.212, TfDchi (Chinese) = 0.008, and the combined frequencies for the TfBvar (variants) = 0.007. Family data (n = 44) were in accordance with an autosomal codominant fashion of inheritance. The use of isoelectric focusing procedure among Japanese will raise the probability of excluding a man falsely accused of paternity to 15.8% as compared with 1.5% when the conventional electrophoretic methods are used.