MUTATION		Codon 32 (T->A) CTG->CAG; codon 98 (G->A) GTG->ATG
AMINO ACID REPLACEMENT		Position 32 Leu->Gln (Hb Medicine Lake); position 98 Val->Met
TYPE OF BETA-THAL		beta°
MECHANISM		Dominant beta-thal due to hyperunstable variant
IDENTIFICATION		Amplification of the beta-globin gene; sequencing of DNA
HEMATOLOGY IN HETEROZYGOTE(S)		Found in a 2-year-old Caucasian girl; parents are normal; hematology at 19 months: Hb 7.8 g/dl; MCV 73 fl; reticulocytes 19.5%; Hb F 6.8%; Hb A2 3.4%
HEMATOLOGY IN HOMOZYGOTE(S)		None observed
OCCURRENCE		In one carrier
HAPLOTYPE		Not determined
FOUND IN COMBINATION WITH ABNORMAL HB(S)		None found
FOUND IN COMBINATION WITH BETA-THAL ALLELE(S)		None found
OTHER INFORMATION		The variant is the same as the unstable Hb Köln but with an additional beta32(B14)Leu->Gln substitution; the variant could not be isolated; the betaX-mRNA is stable; no abnormally spliced mRNA detected

REFERENCES
1.		Coleman, M.B., Lu, Z-H., Smith, C.M., II, Adams, J.G., III, Harrell, A., Plonczynski, M., and Steinberg, M.H.: J. Clin. Invest., 95:503, 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.