Hb S-Antilles	beta6(A3)Glu->Val;
	beta23(B5)Val->Ile

HEMATOLOGY		Mild anemia in the heterozygote; reticulocytosis; ISC; splenomegaly
ELECTROPHORESIS		Hb X moves slightly slower than Hb S in IEF
CHROMATOGRAPHY		Hb X and Hb A readily separate by DEAE-cellulose chromatography
STRUCTURE STUDIES		Tryptic digestion of AE-betaX chain; separation of peptides by reversed phase HPLC; amino acid analysis
DNA ANALYSES		Not reported; presumed mutations GAG->GTG and GTT->ATT at codons 6 and 23
FUNCTION STUDIES		The oxygen affinity of Hb X containing red cells is decreased, particularly when Hb C is also present; Bohr effect is nearly normal
STABILITY		Hb X gives a strongly positive sickling test
OCCURRENCE		Found in many members of a family from Martinique, French West Indies
OTHER INFORMATION		Quantity of Hb X is about that of Hb A in the heterozygote; has occurred in combination with Hb C (causing severe sickle cell syndrome) and with Hb S (severe chronic hemolytic anemia); solubility of deoxyHb X is considerably less than that of Hb S

REFERENCES
1.		Monplaisir, N., Merault, G., Poyart, C., Rhoda, M-D., Craescu, C., Vidaud, M., Galacteros, F., Blouquit, Y., and Rosa, J.: Proc. Natl. Acad. Sci. USA, 83:9363, 1986.

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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.