MUTATION		Codons 14/15 (+G);
		CTG·TGG(Leu;Trp)->CTG·G·TGG
AMINO ACID REPLACEMENT		None
TYPE OF BETA-THAL		beta°
MECHANISM		This frameshift results in the termination of translation at codon 22 (TGA)
IDENTIFICATION		Cloning and DNA sequencing; amplification and DNA sequencing; digestion with BstNI
HEMATOLOGY IN HETEROZYGOTE(S)		Not presented in detail; Hb A2 levels between 5.5 and 6.3%
HEMATOLOGY IN HOMOZYGOTE(S)		None found
OCCURRENCE		In two unrelated Chinese families
HAPLOTYPE		2 [+ O - - - - - +] and 5 [+ O - - - - - +] (differ in HindIII site 3' to beta; 2 is - and 5 is +)
FOUND IN COMBINATION WITH ABNORMAL HB(S)		None known
FOUND IN COMBINATION WITH BETA-THAL ALLELE(S)		With the 41/42 (-TTCT) frameshift; also with the codon 17 (A->T) nonsense mutation
OTHER INFORMATION		Both patients had transfusion-dependent beta-thalassemia major; the carriers are from Guangdong Province, PR China

REFERENCES
1.		Chan, V., Chan, T.K., Kan, Y.W., and Todd, D.: Blood, 72:1420, 1988.

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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.