TYPE HPFH-7; Kenya Ggamma(Agammadeltabeta)°-HPFH (see Fig. 13)
NOTE This anomaly has been listed in A Syllabus of Human Hemoglobin Variants (1996) because the deletion of 22.5 kb which includes the 3' end of the Agamma gene, the psibeta gene, the delta gene, and the 5' end of the beta gene, results in the formation of an Agammabeta chain and thus, in the formation of an abnormal Hb. The description in that Syllabus was as follows:
Hb Kenya Agamma hybrid (Agamma through 81; beta from 86)
HEMATOLOGY Normal in the heterozygote; elevation of Hb F (Ggamma Hb F)
ELECTROPHORESIS Hb X moves slightly slower than Hb S at alkaline pH; about the same by IEF
CHROMATOGRAPHY Hb X was isolated on DEAE-Sephadex or Amberlite IRC-50 columns
STRUCTURE STUDIES Tryptic digestion; separation of peptides by cation exchange chromatography or fingerprinting; amino acid analysis
DNA ANALYSIS Gene mapping has identified the expected 22.5 kb deletion
OCCURRENCE Found in several families from Kenya, Uganda, and other countries near Lake Victoria in Africa
OTHER INFORMATION Quantity in the heterozygote ~15%; with Hb S 16-22%; found in combination with Hb S and Hb A2'; homogeneous distribution of Hb F in red cells
1. Huisman, T.H.J., Wrightstone, R.N., Wilson, J.B., Schroeder, W.A., and Kendall, A.G.: Arch. Biochem. Biophys., 153:850, 1972.
2. Kendall, A.G., Ojwang, P.J., Schroeder, W.A., and Huisman, T.H.J.: Am. J. Hum. Genet., 25:548, 1973.
3. Smith, D.H., Clegg, J.B., Weatherall, D.J., and Gilles, H.M.: Nature, 246:184, 1973.
4. Kendall, A.G. and Ojwang, P.J.: E. Afr. Med. J., 51:434, 1974.
5. Nute, P.E., Wood, W.G., Stamatoyannopoulos, G., Olweny, C., and Failkow, P.J.: Br. J. Haematol., 32:55, 1967.
6. Ojwang, P.J., Nakatsuji, T., Gardiner, M.B., Reese, A.L., Gilman, J.G., and Huisman, T.H.J.: Hemoglobin, 7:115, 1983.

The condition has to be considered an HPFH because of near normal hematological values in the heterozygote, normal Hb A2 production, equal distribution of Hb F among the red cells, and no sickling in the Hb S-Kenya compound heterozygote. Detailed hematological data are shown below.

 A-KenyaS-Kenya A-KenyaS-Kenya
Hb (g/dl)12.412.7Hb A2 (%)2.12.4
PCV (l/l)0.4160.394Hb Kenya (%)14.918.1
RBC (1012/l)5.045.10Hb A (%)71.90
MCV (fl)83.077.0Hb S (%)066.9
MCH (pg)24.625.0Hb F (%)11.112.6
MCHC (g/dl)29.832.3Ggamma (%)96.098.0

Interestingly, a mild microcytosis and hypochromia is often present; a severe iron deficiency anemia can lead to a more serious anemia without sickling (Ref. 2).
1. Huisman, T.H.J., Carver, M.F.H., and Efremov, G.D.: A Syllabus of Human Hemoglobin Variants (1996), The Sickle Cell Anemia Foundation, Augusta, GA, 1996.
2. Waye, J.S., Cai, S-P., Eng, B., Chui, D.H.K., and Francombe, W.H.: Am. J. Hematol., 41:289, 1992.

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.