Hb Ethiopia alpha140(HC2)Tyr->His
CONTACT alpha1beta2 contact
HEMATOLOGY Erythrocytosis in the heterozygote
ELECTROPHORESIS An abnormal band can be observed by IEF close to Hb A; Hb X migrates as Hb A in cellulose acetate at alkaline pH
CHROMATOGRAPHY Hb X can be separated from Hb A by cation exchange HPLC
STRUCTURE STUDIES Tryptic digestion of alphaX chain; reversed phase HPLC to separate the peptides in the tryptic digest; amino acid analysis
DNA ANALYSES Not reported; presumed mutation TAC->CAC; alpha2 or alpha1
FUNCTIONAL STUDIES Moderately increased oxygen affinity; decreased heme-heme interaction; Bohr effect reduced by ~40%
OCCURRENCE Found in a newborn and father of Ethiopian descent; also found in an 81-year-old French male
OTHER INFORMATION Quantity in the heterozygote 19-26%
1. Webber, B.B., Wilson, J.B., Gu, L-H., and Huisman, T.H.J.: Hemoglobin, 16:441, 1992.
2. Wajcman, H., Kister, J., Marden, M., Lahary, A., Monconduit, M., and Galacteros, F.: Biochim. Biophys. Acta, 1180:53, 1992.

This material is from the book A Syllabus of Human Hemoglobin Variants (1996) by Titus H.J. Huisman, Marianne F.H. Carver, and Georgi D. Efremov, published by The Sickle Cell Anemia Foundation in Augusta, GA, USA. Copyright © 1996 by Titus H.J. Huisman. All rights reserved. Neither this work nor any part may be reproduced or transmitted in any form or by any means, electronic or mechanical, microfilming and recording, or by any information storage and retrieval systems, without written permission.