MUTATION		G->A at codon 59 of the alpha1 gene; GGC->GAC
AMINO ACID REPLACEMENT		Gly->Asp at codon 59 (Hb Adana)
TYPE OF ALPHA-THAL		alpha-Thal-2 [alphaalpha(T)/alphaalpha]
MECHANISM		Severely unstable Hb results in a deficient synthesis of functional alpha chains
IDENTIFICATION		Amplification of the alpha1-globin gene; sequencing
HEMATOLOGY IN HETEROZYGOTE(S)		Father (deceased) must have been at least a carrier
HEMATOLOGY IN HOMOZYGOTE(S)		Not observed
OCCURRENCE		In a Turkish 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 variant occurred in combination with a common alpha-thal-1 [-(alpha)20.5 kb] in three children causing a rather severe type of Hb H disease (the mother is an alpha-thal-1 heterozygote): Hb 5.8-8.9 g/dl; MCV 53-106 fl; MCH 19.4-29.5 pg; Hb A2 <1.5%; Hb H not detectable; Hb Bart's 7.0-10.5%. The abnormal Hb was detectable by IEF and cation exchange HPLC

REFERENCES
1.		Çürük, M.A., Dimovski, A.J., Baysal, E., Gu, L-H., Kutlar, F., Molchanova, T.P., Webber, B.B., Altay, Ç., Gürgey, A., and Huisman, T.H.J.: Am. J. Hematol., 44:270, 1993.

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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.