MUTATION -28 (A->G) 
 -30  -25 
  |    |  
CATAAAAG->
CATAGAAG
AMINO ACID REPLACEMENT None
TYPE OF BETA-THAL beta+
MECHANISM Decreased transcription of the beta-globin gene because of reduced binding of erythroid factors
IDENTIFICATION Cloning; amplification of the beta-globin gene; sequencing of the DNA; dot-blot analysis with allele specific probes (ASO)
HEMATOLOGY IN HETEROZYGOTE(S) Not reported
HEMATOLOGY IN HOMOZYGOTE(S) Not reported
OCCURRENCE Chinese and other Southeast Asian populations; see Tables XII and XIII
HAPLOTYPE [? O + + - + - +]
FOUND IN COMBINATION WITH ABNORMAL HB(S) With Hb E
FOUND IN COMBINATION WITH BETA-THAL ALLELE(S) With several found in Southeast Asian persons
OTHER INFORMATION The alpha-mRNA to beta-mRNA ratio in RNA isolated from erythroid cells is about 0.1 in the homozygous patient
       
REFERENCES
1. Orkin, S.H., Sexton, J.P., Cheng, T-C., Goff, S.C., Giardina, P.J.V., Lee, J.I., and Kazazian, H.H., Jr.: Nucleic Acids Res., 11:4727, 1983.

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.