MUTATION Codons 134/135/136/137 [-(G)TGGCTGGTGT(G) and +(G)GCAG(G)]; GTG·GCT·GGT·GTG(Val-Ala-Gly-Val)->GGC·AGG(Gly-Arg)
 
AMINO ACID REPLACEMENT See above
TYPE OF BETA-THAL Dominant inclusion body beta-thal trait
MECHANISM This complex change modifies and shortens the beta chain (144 amino acids residues); it is unstable and readily catabolized, causing this TYPE OF BETA-THAL
IDENTIFICATION Amplification of the beta-globin gene; DNA sequencing; dot-blot analysis with mutation specific probes
HEMATOLOGY IN HETEROZYGOTE(S) Proband; mother; grandfather
Sex-AgeF-16 F-38 M-58
Hb (g/dl)10.4 10.6 12.6
MCV (fl)79.0 75.0 76.0
MCH (pg)21.9 21.9 24.0
Hb A2 (%)4.0 4.8 5.3
Hb F (%)3.5 2.2 -
Beta/Alpha Ratio0.6 0.85 -

HEMATOLOGY IN HOMOZYGOTE(S) None
OCCURRENCE Found in three members of a Portuguese family
HAPLOTYPE Not determined
FOUND IN COMBINATION WITH ABNORMAL HB(S) None
FOUND IN COMBINATION WITH BETA-THAL ALLELE(S) None
OTHER INFORMATION The abnormal Hb or betaX chain could not be detected by electrophoretic or chromatographic procedures; stability tests were negative
       
REFERENCES
1. Öner, R., Öner, C., Wilson, J.B., Tamagnini, G.P., Ribeiro, L.M.L., and Huisman, T.H.J.: Br. J. Haematol., 79:306, 1991.

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.