TYPE Indian GgammaAgamma(deltabeta)°-Thal (see Fig. 14)
CAUSE A large deletion removing DNA 1 kb 3' of the Agamma-globin gene to >10 kb 3' of the beta gene, including the Alu repeats and L1 repetitive sequences. The deletion size is 32.6 kb which is similar to the 36 kb Turkish and Black Ggamma(Agammadeltabeta)°-thal.
DETECTION Gene mapping with different probes and enzymes. The abnormal 15 kb BclI fragment was cloned and sequencing revealed the exact breakpoint.
PHENOTYPE The patient had high Hb F (16.6%) which was heterogeneously distributed in the red cells. The Ggamma:Agamma ratio was 79:21; Hb A2 was normal (2.3%). The patient was mildly anemic and the red cells were microcytic. Hematological data: Hb 11.5 g/dl; PCV 0.33 l/l; RBC 4.5 x 1012/l; MCV 78 fl; MCH 26 pg; MCHC 33.9 g/dl.
DISTRIBUTION The (deltabeta)°-thal has only been found in one Indian subject.
1. Mishima, N., Landman, H., Huisman, T.H.J., and Gilman, J.G.: Br. J. Haematol., 73:375, 1989.
2. Mishima, N. and Gilman, J.G.: Blood, 78:69a (Suppl. 1), 1991.
3. Gilman, J.G., Brinson, E.C., and Mishima, N.: Br. J. Haematol., 82:417, 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.