Abstract
The proposita was a Thai female showing signs of a mild anemia (Hb: 11.4 g/dl; RBC: 4.91 × 106/mm3; reticulocytes: 2.4%; MCV: 70 fl; MCHC: 23.3 g/dl). Hemoglobins were isolated by DEAE-cellulose chromatography in the following relative amounts: Hb E + Hb A2 = 53%; Hb F0 = 30.0%; Hb δβ-Lepore = 12.7%; Hb F1 = 4.3%. The βE and δβ-Lepore chains were isolated by CM-cellulose chromatography and were subjected to tryptic peptide mapping on paper in comparison to normal βA chains. Amino acid analysis of selected peptides permitted unambiguous identification of the abnormal hemoglobins as Hb E [β26(B8)GluLys] and Hb Lepore-Washington-Boston, which has a δ chain sequence for residues 1-87, and a β chain sequence for residues 116-146. The presence of a Lepore hemoglobin was further confirmed by Pst I digestion of the proposita's DNA. The association of the two hemoglobin variants gave rise to elevated levels of Hb F.