Hb Chad	alpha23(B4)Glu->Lys

ALSO KNOWN AS		E-Keelung
CONTACT		External
HEMATOLOGY		Normal in heterozygotes without alpha-thal
ELECTROPHORESIS		Hb X moves to the position of Hb E or Hb A2 on starch gel at alkaline pH; excellent separation by IEF
CHROMATOGRAPHY		Hb X separates from Hb A in cation and anion exchange HPLC
STRUCTURE STUDIES		Tryptic digestion; separation of peptides by fingerprinting; amino acid analysis
DNA ANALYSES		A GAG->AAG mutation at codon 23 of the -alpha(3.7 kb) alpha-thal-2 gene has been reported in a family from Surinam (Ref. 3)
FUNCTIONAL STUDIES		Not reported
STABILITY		Not reported
OCCURRENCE		Reported in a few Black, Chinese, and Japanese families
OTHER INFORMATION		Quantity in heterozygotes 14.5-24%; those with the mutation on the -alpha(3.7 kb) alpha-thal-2 gene had ~31.5% Hb X

REFERENCES
1.		Boyer, S.H., Crosby, E.F., Fuller, G.F., Ulenurm, L., and Buck, A.A.: Am. J. Hum. Genet., 20:570, 1968.
2.		Blackwell, R.Q., Weng, M-I., and Huang, J-T.: Trop. Geogr. Med., 25:393, 1973.
3.		Codrington, J.F., Codrington, F.A., Wisse, J.H., Wilson, J.B., Webber, B.B., Wong, S.C., and Huisman, T.H.J.: Hemoglobin, 13:543, 1989.

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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.