TYPE HPFH-4; Italian (see Fig. 13)
CAUSE This type is caused by a deletion that extends 5 kb from the 5' to the delta gene to ~30 kb 3' to the beta gene, thus removing the 3'HS-1 site, located ~20 kb to the beta gene. The 3' breakpoint is close to that of the Indian HPFH-3, while the 5' breakpoint is in close proximity to that of the Spanish (deltabeta)°-thal and Black HPFH-1. The deletion removes the delta and beta genes, the L1 repeat, and ends ~10 kb downstream from the 3'HS-1.
DETECTION Gene mapping with various probes and enzymes.
PHENOTYPE Heterozygotes have almost normal hematological parameters: Hb 11.8-16.6 g/dl; MCV 74-91 fl; MCH 24-32 pg; Hb A2 1.7-2.0%. The Hb F value in one patient was 14% but it ranged from 21-30% in the others. The distribution of Hb F in RBC is pancellular and Ggamma levels are 31-39%. Globin chain synthesis was normal.
DISTRIBUTION Italian HPFH-4 was observed in nine subjects belonging to three different families from Southern Italy.
1. Saglio, G., Camaschella, C., Serra, A., Bertero, T., Rege Cambrin, G., Guerrasio, A., Mazza, U., Izzo, P., Terragni, F., Giglioni, B., Comi, P., and Ottolenghi, S.: Blood, 68:646, 1986.

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.