Hb J-Singapore	alpha78(EF7)Asn->Asp;
	alpha79(EF8)Ala->Gly

CONTACT		External; near central cavity
HEMATOLOGY		Normal in the heterozygote
ELECTROPHORESIS		Hb X and Hb A separate at alkaline pH; Hb X moves to the position of Hb J
CHROMATOGRAPHY		Hb X was isolated on a DEAE-Sephadex column
STRUCTURE STUDIES		Tryptic digestion; separation of peptides by fingerprinting; amino acid analysis; sequence analysis
DNA ANALYSES		Not reported; presumed mutations AAC->GAC and GCG->GGG at codons 78 and 79 (alpha2 or alpha1)
FUNCTION STUDIES		Not reported
STABILITY		Not reported
OCCURRENCE		Found in a Malay family
OTHER INFORMATION		Quantity in the heterozygote 22-24%; it is possible that this is not a true double variant; the Asn->Asp substitution might be due to deamidation in vivo

REFERENCES
1.		Blackwell, R.Q., Wong, H.B., Liu, C-S., and Weng, M-I.: Biochim. Biophys. Acta, 278:482, 1972.

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This material is from the book A Syllabus of Human Hemoglobin Variants (1996) by Titus H.J. Huisman, Marianne F.H. Carver, and Georgi D. Efremov, published by The Sickle Cell Anemia Foundation in Augusta, GA, USA. Copyright © 1996 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 written permission.