Hb Higashitochigi (or HT)	beta24(B6) or beta25(B7) Gly->0

HEMATOLOGY		MetHb; cyanosis; normal hematology; reticulocytosis
ELECTROPHORESIS		Hb X focuses as a dark brown band behind Hb A and Hb F
CHROMATOGRAPHY		Hb X separates from Hb A on an anion exchange HPLC column (between Hb A and Hb A2); the betaX chain separates from betaA and alpha on a reversed phase HPLC column (elution order: betaA, alpha, betaX)
STRUCTURE STUDIES		Tryptic digestion of betaX chain; separation of peptides by reversed phase HPLC; amino acid analysis; sequencing
DNA ANALYSES		A deletion of three nts at codons 24-25 (GGTGGT->GGT)
FUNCTION STUDIES		MetHb formation
STABILITY		Unstable
OCCURRENCE		Found in a Japanese child, but not in the parents
OTHER INFORMATION		MetHb 16.5%; spectrum slightly abnormal; normal after addition of KCN

REFERENCES
1.		Fujisawa, K., Yamashiro, Y., Hattori, Y., Ohba, Y., Kajita, T., Kageyama, S., and Arita, J.: Hemoglobin, 17:467, 1993.

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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.