Hb Tarrant	alpha126(H9)Asp->Asn

CONTACT		alpha1beta1 contact
HEMATOLOGY		Mild erythrocytosis in the homozygote
ELECTROPHORESIS		Hb X moves between Hb S and Hb F (close to Hb F) at alkaline pH and to the position of Hb S on citrate agar at acidic pH
CHROMATOGRAPHY		Hb X was isolated on a DEAE-cellulose column
STRUCTURE STUDIES		Tryptic digestion; separation of peptides by cation exchange chromatography; amino acid analysis; chymotrypsin; amino peptidase; thermolysin
DNA ANALYSES		Not reported; presumed mutation GAC->AAC; alpha2 or alpha1
FUNCTIONAL STUDIES		Increased oxygen affinity; decreased cooperativity; normal Bohr effect
STABILITY		Normal
OCCURRENCE		Found in a few Mexican families
OTHER INFORMATION		Quantity in heterozygotes 20-25%; quantity in homozygotes 50%

REFERENCES
1.		Moo-Penn, W.F., Jue, D.L., Johnson, M.H., Wilson, S.M., Therrell, B., Jr., and Schmidt, R.M.: Biochim. Biophys. Acta, 490:443, 1977.
2.		Ibarra, B., Vaca, G., Cantu, J.M., Wilson, J.B., Lam, H., Stallings, M., Gravely, M.E., and Huisman, T.H.J.: Hemoglobin, 5:337, 1981.

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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.