The Clinical and Haematological Findings in Children Inheriting Two Types of Thalassaemia: High‐A2 Type β‐Thalassaemia, and High‐F Type or δβ‐Thalassaemia

Summary. Eleven children who are double heterozygotes for β‐ and δβ‐thalassaemia are described. Of their parents one was always heterozygous for β‐(A2) thalassaemia (increased Hb A2), and the other for the high F variant or δβ‐thalassaemia (increased Hb F). The clinical syndrome resulting from the combination of β‐ and δβ‐thalassaemia shows some heterogeneity, but in general is of intermediate severity. Red cell abnormalities were considerable, Hb F was very high (mean 70.3 ± 12.6%), Hb A2 was low or normal (mean 2.36 ± 1.52%), and Hb A was absent in five patients. Hb F was nearly homogeneously distributed in the red cells of most patients. These findings are explained as the outcome of a mutation which suppresses δ‐ and β ‐chain synthesis which is associated with a genetically determined increased production of γ‐ chains. Copyright © 1973, Wiley Blackwell. All rights reserve