-.-(SA),.deletion.of.22.8-23.7.kb.involv.html


MUTATION		- -(SA); deletion of 22.8-23.7 kb involving both alpha-globin genes (see Fig. 24)

AMINO ACID REPLACEMENT		None
TYPE OF ALPHA-THAL		alpha-Thal-1 [- -/]
MECHANISM		Deletion of both alpha-globin genes results in the absence of any alpha-mRNA
IDENTIFICATION		Gene mapping
HEMATOLOGY IN HETEROZYGOTE(S)		Hb 9.4-14.1 g/dl; MCV 61-70 fl; MCH 18.5-22.5 pg; Hb A₂ 1.6-2.2%; no Hb H
HEMATOLOGY IN HOMOZYGOTE(S)		None
OCCURRENCE		In a few families from South Africa
HAPLOTYPE		Not determined
FOUND IN COMBINATION WITH ABNORMAL HB(S)		Not reported
FOUND IN COMBINATION		With -alpha(3.7 kb) causing Hb H disease: Hb 6.1-10.3 g/dl; MCV 59-66 fl; MCH 17.5-19.5 pg; Hb A₂ 0.3-0.6%; Hb H 2.9-8.3%; alpha/beta ratio 0.4-0.5. With -alpha(4.2 kb) causing Hb H disease: Hb 8.8-8.9 g/dl; MCV 60.0-63.5 fl; MCH 18 pg; Hb A₂ 0.7%; Hb H 2.0-3.5%; alpha/beta ratio 0.4
OTHER INFORMATION		None


REFERENCES
1.		Mathew, C.G.P., Rousseau, J., Rees, J.S., and Hartley, E.H.: Br. J. Haematol., 55:103, 1983.
2.		Vandenplas, S., Higgs, D.R., Nicholls, R.D., Bester, A.J., and Mathew, C.G.P.: Br. J. Haematol., 66: 539, 1987.
3.		Fei, J-Y., Liu, J-C., Jogessar, V.B., Westermeyer, K.R., Bridgemohan, R., and Huisman, T.H.J.: Acta Haematol., 87:11, 1992.

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.