TYPE Malay-2 Ggamma(Agammadeltabeta)°-Thal (see Fig. 16)
 
CAUSE A large deletion that removes the Agamma, delta, and beta genes. The 5' end of the deletion is between the AhaIII and ApaI sites, 0.2 to 0.4 kb 5' to the Agamma gene and the 3' end is beyond sequences 17 to18 kb 3' to the beta gene.
DETECTION Gene mapping with different enzymes and probes.
PHENOTYPE The homozygote has a moderate anemia with a thalassemia intermedia-like phenotype; the hematological data are: Hb 11.8 g/dl; Hb F 100% (contained Ggamma chains only); PCV 0.33 l/l; RBC 4.98 x 1012/l; MCV 67; fl; MCV 23.7 pg; MCHC 35.5 g/dl; reticulocytes 3%. He had jaundice, hepatosplenomegaly, and thalassemic RBC morphology. The peripheral blood smear was characterized by a mild anisopoikilocytosis, hypochromia, and target cells.
DISTRIBUTION The proband was an adopted, 11-year-old Malay boy, without known relatives; he is homozygous for the deletion.
       
REFERENCES
1. George, E., Faridah, K., Trent, R.J., Padanilam, B.J., Huang, H.J., and Huisman, T.H.J.: Hemoglobin, 10:353, 1986.


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.