MUTATION Codon 127 (A->G); CAG(Gln)->CGG(Arg)
 
AMINO ACID REPLACEMENT Gln->Arg (Hb Dieppe)
TYPE OF BETA-THAL Dominant inclusion body beta-thal trait
MECHANISM The mutation results in the synthesis of a highly unstable betaX chain which is removed from circulation by proteolysis, causing a beta-thal condition
IDENTIFICATION DGGE of amplified DNA fragments; sequencing
HEMATOLOGY IN HETEROZYGOTE(S) Chronic anemia (Hb 7.5 g/dl); occasional transfusion; splenomegaly; hemosiderosis; normal Hb A2; Hb F 18.0%; beta/alpha in vitro chain ratio 0.48
HEMATOLOGY IN HOMOZYGOTE(S) None
OCCURRENCE In a 31-year-old French female
HAPLOTYPE Not reported
FOUND IN COMBINATION WITH ABNORMAL HB(S) None
FOUND IN COMBINATION WITH BETA-THAL ALLELE(S) None
OTHER INFORMATION Unstable Hb or betaX chain was not detected
       
REFERENCES
1. Girodon, E., Ghanem, N., Vidaud, M., Riou, J., Martin, J., Galactéros, F., and Goossens, M.: Ann. Hematol., 65:188, 1992.


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.