MUTATION Codon 67 (-TG); GTG(Val)->--G
 
AMINO ACID REPLACEMENT None
TYPE OF BETA-THAL beta°
MECHANISM The loss of the two nucleotides causes a frameshift with a stop codon at the new codon 71 (TAG) resulting in a premature termination of translation
IDENTIFICATION Amplification of the beta-globin gene; DNA sequencing
HEMATOLOGY IN HETEROZYGOTE(S) Hb 10.7-11.5 g/dl; MCV 59-64 fl; Hb A2 4.8-6.6%; Hb F 0.6-1.4%
HEMATOLOGY IN HOMOZYGOTE(S) Not reported
OCCURRENCE In a Filipino family
HAPLOTYPE Not reported
FOUND IN COMBINATION WITH ABNORMAL HB(S) None
FOUND IN COMBINATION WITH BETA-THAL ALLELE(S) The proband is a child with severe beta-thal major who is a compound heterozygote for this frameshift and a second beta-thal allele which involves the deletion of the entire beta-globin gene; hematology at 9 months: Hb 6.2 g/dl; MCV 74.1 fl; Hb A2 2.5%; Hb F 97.5%
OTHER INFORMATION None
       
REFERENCES
1. Eng, B., Chui, D.H.K., Saunderson, J., Olivieri, N.F., and Waye, J.S.: Hum. Mutat., 2:374, 1993.


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.