MUTATION IVS-II-849 (A->G); 
       105         105
CAACAG^CTC->CAACGG^CTC
AMINO ACID REPLACEMENT None
TYPE OF BETA-THAL beta°
MECHANISM The A->G change in the dinucleotide AG, needed for the proper splicing, will abolish this process, and no normal mRNA is produced
IDENTIFICATION Cloning and amplification of the beta-globin gene; DNA sequencing; dot-blot analysis with allele specific probes
HEMATOLOGY IN HETEROZYGOTE(S) Average of five heterozygotes (Ref. 3): Hb 10.8 g/dl; MCV 85 fl; MCH 19.3 pg; Hb A2 5.7%; Hb F 1.0-4.9%
HEMATOLOGY IN HOMOZYGOTE(S) Not reported
OCCURRENCE In a few Black families
HAPLOTYPE Not determined
FOUND IN COMBINATION WITH ABNORMAL HB(S) Not reported
FOUND IN COMBINATION WITH BETA-THAL ALLELE(S) Found in combination with the -29 (A->G) mutation (not transfused): Hb 4.7-9.1 g/dl; MCV 74-84 fl; MCH 18.4-25.7 pg; Hb A2 2.0-5.1%; Hb F 75.8-86.1%; Hb A 11.9-19.5%
OTHER INFORMATION None
       
REFERENCES
1. Antonarakis, S.E., Irkin, S.H., Cheng, T-C., Scott, A.F., Sexton, J.P., Trusko, S.P., Charache, S., and Kazazian, H.H., Jr.: Proc. Natl. Acad. Sci. USA, 81:1154, 1984.
2. Atweh, G.F., Anagnou, N.P., Shearin, J., Forget, B.G., and Kaufman, R.E.: Nucleic Acids Res., 13:777, 1985.
3. Codrington, J., Anijs, J., Wisse, J.H., Codrington, F.A., Li, H., Kutlar, F., Ramachandran, M., and Huisman, T.H.J.: Acta Haematol., 84:135, 1990.

This material is from the book A Syllabus of Thalassemia Mutations (1997) by Titus H.J. Huisman, Marianne F.H. Carver, and Erol Baysal, published by The Sickle Cell Anemia Foundation in Augusta, GA, USA. Copyright © 1997 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 permission in writing from the Author.