Hb Osler	beta145(HC2)Tyr->Asp or Asn

ALSO KNOWN AS		Fort Gordon; Nancy
NOTE:		A study has recently appeared identifying a TAT->AAT mutation as the cause for the abnormal Hb Osler in the original family. This mutation corresponds to a Tyr->Asn replacement; the asparagine residue should readily be deaminated to aspartic acid (Ref. 6). Ref. 7 reports a new case with Hb Osler in a Black family; the mutation reported is TAT->GAT or Tyr->Asp. A further comparison of samples is required to solve this little mystery.
CONTACT		Internal; alpha2beta1 contact
HEMATOLOGY		Erythrocytosis in the heterozygote (PCV 0.62-0.69 l/l)
ELECTROPHORESIS		Hb X and Hb A separate at alkaline pH; Hb X moves ahead of Hb A
CHROMATOGRAPHY		Hb X and Hb A can be separated by cation and anion exchange chromatography
STRUCTURE STUDIES		Tryptic digestion of betaX chain; separation of peptides by cation exchange chromatography or fingerprinting; amino acid analysis; carboxypeptidase A
DNA ANALYSES		Not reported; presumed mutation TAT->GAT at codon 145
FUNCTION STUDIES		Increased oxygen affinity; decreased Bohr effect and cooperativity
STABILITY		Normal
OCCURRENCE		Found in 11 members of a Black family; a 20-year-old Black male in the army; a French female, and in five members of a family of unspecified racial or ethnic background (Ref. 5)
OTHER INFORMATION		Quantity in the heterozygote 30%

REFERENCES
1.		Charache, S., Brimhall, B., and Jones, R.T.: Johns Hopkins Med. J., 136:132, 1975.
2.		Kleckner, H.B., Wilson, J.B., Lindeman, J.G., Stevens, P.D., Niazi, G., Hunter, E., Chen, C.J., and Huisman, T.H.J.: Biochim. Biophys. Acta, 400:343, 1975.
3.		Gacon, G., Wajcman, H., Labie, D., and Vigneron, C.: FEBS Lett., 56:39, 1975.
4.		Arnone, A., Gacon, G., and Wajcman, H.: J. Biol. Chem., 251:5875, 1976.
5.		Butler, W.M., Spratling, L., Kark, J.A., and Schoomaker, E.B.: Am. J. Hematol., 13:293, 1982.
6.		Hutt, P.J., Donaldson, M., Fairbanks, V., Hoyer, J., Thibodeau, S., Moxness, M., Green, M., and Jones, R.: Blood, 86:486a (Suppl. 1), 1995.
7.		Kelly, K.M., Kattamis, A., Fortina, P., and Ohene-Frempong, K.: Blood, 86:651a (Suppl. 1), 1995.

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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.