MUTATION -31 (A->G) 
 -30  -25 
  |    |  
CATAAAAG->
CGTAAAAG
AMINO ACID REPLACEMENT None
TYPE OF BETA-THAL beta+
MECHANISM A reduction in transcription of the beta-globin gene because of a decreased binding of transcriptional factors
IDENTIFICATION Cloning of the beta-globin gene; DNA sequencing
HEMATOLOGY IN HETEROZYGOTE(S) Parents were heterozygotes: Hb A2 4.6, 4.9%; Hb F 0.6, 1.2%
HEMATOLOGY IN HOMOZYGOTE(S) Proband was homozygous: Hb 7.2 g/dl; MCV 74.4 fl; MCH 16.7 pg; reticulocytes 3.6%; Hb A2 5.9%; Hb F 14%; (alkaline denaturation); beta/alpha ratio 0.34
OCCURRENCE In an Japanese family
HAPLOTYPE [- O + + - + + -]
FOUND IN COMBINATION WITH ABNORMAL HB(S) None
FOUND IN COMBINATION WITH BETA-THAL ALLELE(S) None
OTHER INFORMATION In vitro expression studies indicate a reduction in beta-globin mRNA production of ~45%
       
REFERENCES
1. Takihara, Y., Nakamura, T., Yamada, H., Takagi, Y., and Fukumaki, Y.: Blood, 67:547, 1986.

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.