MUTATION 5'UTR; +33 (C->G)
 
AMINO ACID REPLACEMENT None
TYPE OF BETA-THAL beta+ (silent)
MECHANISM Decreased transcription
IDENTIFICATION Amplification of the beta-globin gene; DNA sequencing
HEMATOLOGY IN HETEROZYGOTE(S) Hb A2 3.6%; alpha/beta ratio 0.98; normal red cell indices (Ref. 1). Others (Ref. 2); Hb 16.0, 12.1, 10.6 g/dl; MCV 75.8, 86.5, 81.7 fl; MCH 25.5, 29.1, 25.8 pg; Hb A2 1.4, 2.9, 2.7%; Hb F 0.2, 1.6, 0.7%; alpha/beta ratio 1.0, 1.5, 1.3
HEMATOLOGY IN HOMOZYGOTE(S) Not reported
OCCURRENCE In a Greek Cypriot family (Ref. 1); in two additional Greek Cypriot families (Ref. 2)
HAPLOTYPE II [- O + + - + + +]
FOUND IN COMBINATION WITH ABNORMAL HB(S) Not reported
FOUND IN COMBINATION WITH BETA-THAL ALLELE(S) Proband was compound heterozygote for this mutation and for IVS-I-110 (G->A); Hb 7.8 g/dl; MCV 66 fl; MCH 18.5 pg; Hb A2 4.7%; Hb F 3.7%; beta/alpha in vitro globin synthesis ratio 0.2; transfusions not required (Ref. 1); others (Ref. 2):
Mutation: +33 (C->G) + Sex-Age Hb MCV MCH Hb A2 Hb F alpha/beta
CD 39 (C->T) M-27 11.7 65.9 19.1 6.6 0.9 -
Same M-25 10.7 72.3 22.8 6.2 4.8 4.2
Same F-20 10.5 57.1 18.1 5.4 1.2 2.7
IVS-I-1 (G->A) M-74 7.1 64.2 18.6 6.35 3.5 5.0
IVS-I-110 (G->A) F-24 9.4 64.3 19.7 5.46 3.5 -
Same F-18 10.4 63.6 20.1 5.27 4.1 2.8

OTHER INFORMATION mRNA analysis showed 25-35% normal mRNA
       
REFERENCES
1. Traeger-Synodinos, J., Maragoudaki, E., Vrettou, C., Michael, Th., Kanavakis, E., and Kattamis, C.: Br. J. Haematol., 93 (Suppl. 2) (Abstract 100), 1996.
2. Ho, P.J., Rochette, J., Fisher, C.A., Wonke, B., Jarvis, M.K., Yardumian, A., and Thein, S.L.: Blood, 87:1170, 1996.


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.