Heterogeneity of fetal hemoglobin in severe alpha-thalassemia.

The heterogeneity of residue 136 of the gamma-chain of human hemoglobin has been determined for a patient afflicted with severe alpha-thalassemia. Separation of the cord blood sample into the various constituent hemoglobins A, F, FI and Bart's were done on a column packed with DEAE Sephadex. The amount of glycine or alanine at position 136 was determined for hemoglobins F, FI and Bart's. The ratios determined for all three hemoglobins indicated that the G gamma/A gamma ratio is the same for all three fractions and is similar to that observed in normal cord blood samples.