MUTATION		- -(MA); deletion of ~22 kb involving both alpha genes (see Fig. 24)
AMINO ACID REPLACEMENT		None
TYPE OF ALPHA-THAL		alpha-Thal-1 [- -/]
MECHANISM		The deletion involves both alpha-globin genes; absence of functional alpha-mRNAs
IDENTIFICATION		Gene mapping; see diagram below
		Positions of the restriction sites and the sizes of the fragments for several enzymes for a chromosome with a zeta-globin gene triplication. The extent of the deletion is shown at the bottom (black bar), with the limits of the breakpoints indicated by white bars. [Figure not yet available on-line.]
HEMATOLOGY IN HETEROZYGOTE(S)		Hb 12-13 g/dl; MCV 70-72 fl; MCH 23-35 pg; alpha/beta ratio 0.6-0.7
HEMATOLOGY IN HOMOZYGOTE(S)		None
OCCURRENCE		In a few Spanish families
HAPLOTYPE		Not determined
FOUND IN COMBINATION WITH ABNORMAL HB(S)		Not reported
FOUND IN COMBINATION		With the -alpha(3.7 kb) deletion causing Hb H disease: Hb 10-11 g/dl; MCV 70-72 fl; MCH 20-22 pg; Hb A2 0.8%; Hb H 5-7%; inclusion bodies present; alpha/beta ratio 0.4-0.5
OTHER INFORMATION		Deletion is associated with a zeta-globin gene triplication

REFERENCES
1.		Gonzalez-Redondo, J.M., Gilsanz, F., and Ricard, P.: Hemoglobin, 13:103, 1989.
2.		Villegas, A., Sánchez, J., Carreño, D.L., Ropero, P., González, F.A., Espinós, D., Peñalver, M.A., and Lozano, M.: Am. J. Hematol., 49:294, 1995.

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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.