MUTATION		- -(THAI); a deletion of 34-38 kb involving the alpha1, alpha2, and zeta genes (see Fig. 24)
AMINO ACID REPLACEMENT		None
TYPE OF ALPHA-THAL		alpha-Thal-1 [- -/]
MECHANISM		Absence of the alpha2-, alpha1-, and zeta-globin genes result in no synthesis of alpha-, beta-, or zeta-mRNAs
IDENTIFICATION		Gene mapping
HEMATOLOGY IN HETEROZYGOTE(S)		Microcytosis; hypochromia
HEMATOLOGY IN HOMOZYGOTE(S)		Fetuses with a homozygosity for this deletion (hydrops fetalis) are usually aborted because of the complete absence of zeta chain synthesis
OCCURRENCE		In Southeast Asian families (Thailand)
HAPLOTYPE		Not determined
FOUND IN COMBINATION WITH ABNORMAL HB(S)		Not reported
FOUND IN COMBINATION WITH alpha-THAL ALLELE(S)		Found in a few patients with Hb H disease [-alpha(3.7) or -alpha(CS)]: Hb ~10 g/dl; MCV 60-65 fl; MCH 20-24 pg; Hb H 15-20%
OTHER INFORMATION		None

REFERENCES
1.		Fischel-Ghodsian, N., Vickers, M.A., Seip, M., Winichagoon, P., and Higgs, D.R.: Br. Haematol., 70: 233, 1988.

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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.