Hb Saint Etienne beta92(F8)His->Gln
CONTACT Heme contact; proximal histidine
HEMATOLOGY Hemolytic anemia of variable severity in the heterozygote
ELECTROPHORESIS Hb X and Hb A separate at alkaline pH; Hb X moves between Hb S and Hb C
CHROMATOGRAPHY Hb X can be isolated by DEAE-Sephadex chromatography; Hb X elutes before Hb A
STRUCTURE STUDIES Tryptic digestion of AE-betaX chain; separation of peptides by fingerprinting or by cation exchange chromatography; amino acid analysis; sequencing
DNA ANALYSES Not reported; presumed mutation CAC->CAA or CAG at codon 92
FUNCTION STUDIES Normal oxygen affinity for whole cells; increased oxygen affinity for 'stripped' pure Hb X; no Bohr or 2,3-DPG effects; decreased cooperativity
STABILITY Unstable; dissociates into dimers, particularly at higher pH
OCCURRENCE Found in a young French male and in a Turkish male, but not in their parents
OTHER INFORMATION Variant carries heme only on its alpha chains; this affects quantitation of the abnormal Hb; quantity in heterozygotes estimated at 25% which is likely too low; high level (20%) of Hb F present in the French patient with the least severe disease
1. Cohen-Solal, M., Thillet, J., Gailardon, J., and Rosa, J.: Eur. J. Clin. Biol. Res., 17:988, 1970.
2. Aksoy, M., Erdem, S., Efremov, G.D., Wilson, J.B., Huisman, T.H.J., Schroeder, W.A., Shelton, J.R., Shelton, J.B., Ulutin, O.N., and Muftuoglu, A.: J. Clin. Invest., 51:2380, 1972.
3. Beuzard, Y., Courvalin, J.Cl., Cohen-Solal, M., Garel, M.C., and Rosa, J.: FEBS Lett., 27:76, 1972.
4. Rosa, J., Brizard, C.P., Gibaud, A., Beuzard, Y., Courvalin, J.Cl., Cohen-Solal, M., Garel, M.C., and Thillet, J.: Nouv. Rev. Fr. d'Hematol., 12:691, 1972.

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.