MUTATION		12,620 bp deletion (see Fig. 4); the Dutch deletion
AMINO ACID REPLACEMENT		None
TYPE OF BETA-THAL		beta°
MECHANISM		No beta chain production; considerable increase in gamma chain formation
IDENTIFICATION		Gene mapping; cloning; amplification; DNA sequencing
HEMATOLOGY IN HETEROZYGOTE(S)		Hb 12.4-13.0 g/dl; MCV 65-70 fl; MCH 18-24 pg;
		Hb A2 6.8, 5.9, 6.3, 6.0, 6.4, 8.6, 5.1, 6.5, 5.9, 5.5, 6.1%;
		Hb F 8.0, 10.7, 6.7, 10.4, 4.6, 4.1, 9.4, 5.9, 5.5, 7.7, 10.9%
HEMATOLOGY IN HOMOZYGOTE(S)		Two homozygotes: Hb 10.9, 13.1 g/dl; MCV ~73 fl; MCH 20-25 pg; Hb A2 2.0, 2.4%; Hb A 0%; Hb F 98.0, 97.6%
OCCURRENCE		In a large Dutch family
HAPLOTYPE		Not determined
FOUND IN COMBINATION WITH ABNORMAL HB(S)		Not reported
FOUND IN COMBINATION WITH BETA-THAL ALLELE(S)		Not reported
OTHER INFORMATION		The deletion includes the entire beta-globin gene

REFERENCES
1.		Schokker, R.C., Went, L.N., and Bok, J.: Nature, 209:44, 1966.
2.		Gilman, J.G., Huisman, T.H.J., and Abels, J.: Br. J. Haematol., 56:339, 1984.
3.		Gilman, J.G.: Br. J. Haematol., 67:369, 1987.

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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.