Hb J-Singapore alpha78(EF7)Asn->Asp;
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)
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
1. Blackwell, R.Q., Wong, H.B., Liu, C-S., and Weng, M-I.: Biochim. Biophys. Acta, 278:482, 1972.

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.