MUTATION Initiation codon ATG->GTG
 
AMINO ACID REPLACEMENT Met->Val
TYPE OF BETA-THAL beta°
MECHANISM Defective mRNA translation; absence of beta chain production; initiation changed to codons 21-22; termination at codons 60-61 (TGA)
IDENTIFICATION Cloning of the amplified beta-globin gene; DNA sequencing; dot-blot analysis with allele specific probes; NcoI digestion (a restriction site is lost); ASO
HEMATOLOGY IN HETEROZYGOTE(S) Hb 9.1-11.6 g/dl; MCV 53-70 fl; MCH 16.1-21.7 pg; reticulocytes 3.1-8.2%; Hb A2 6.0-6.7%; Hb F 0.8-7.1%; alpha/beta ratio 0.47-0.55
HEMATOLOGY IN HOMOZYGOTE(S) Not reported
OCCURRENCE Found in a few Japanese families
HAPLOTYPE Not done
FOUND IN COMBINATION WITH ABNORMAL HB(S) Not reported
FOUND IN COMBINATION WITH BETA-THAL ALLELE(S) Not reported
OTHER INFORMATION It is surprising to see that some of the subjects are rather severely affected, alpha-globin gene status was not determined
       
REFERENCES
1. Hattori, Y., Yamashiro, Y., Ohba, Y., Miyaji, T., Morishita, M., Yamamoto, Ku., Yamamoto, Ki., Narai, S., and Kimura, A.: Hemoglobin, 15:317, 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.