TYPE HPFH-5; Italian (see Fig. 13)
CAUSE The deletion starts 3.2 kb 5' to the delta gene, removes both the delta and beta genes, and terminates 0.7 kb 3' to the beta gene; the total length of the deletion is 12.9 kb. The size of this deletion is similar to those of Black, Sicilian, Laotian, and Thai (deltabeta)°-thal. The Italian HPFH-5 is the smallest of the HPFH deletions reported thus far.
DETECTION Gene mapping and sequencing. Direct sequencing of PCR-amplified fragments spanning the 5' and 3' breakpoints showed that the 5' breakpoint is located 141 bp downstream from the XbaI site in the inter-Alu region, and the 3' breakpoint between positions 692 and 695 bp 3' to the poly A site of the beta gene.
PHENOTYPE The hematology is nearly normal in the two heterozygotes: Hb 14.0 and 13.6 g/dl; MCV 81 and 80 fl; MCH 25 and 26 pg; Hb A2 2.1 and 2.0%; Hb F 20.0 and 16.0%; Agamma 83.0 and 85.0%; alpha/non-alpha 1.15. Distribution of the Hb F in the erythrocytes, evaluated by immunofluorescence with an anti-gamma-monoclonal antibody, was pancellular. The possibility of the coexistence of nondeletional Agamma-HPFH, which may be responsible for the marked elevation in the Agamma chain synthesis, was excluded by sequencing of the Agamma promoter region from position -264 to the Agamma gene Cap site.
DISTRIBUTION HPFH-5 was found in two brothers from Sicily.
1. Camaschella, C., Serra, A., Gottardi, E., Alfarano, A., Revello, D., Mazza, U., and Saglio, G.: Blood, 75:1000, 1990.

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.