The molecular basis of HbH disease in Greece

Summary. Globin gene mapping in 16 Greek individuals with HbH disease and their parents has demonstrated the occurrence of several HbH genotypes brought about by the interaction of two α+‐thalassaemia and two α+‐thalassaemia haplotypes. Eight of the 16 patients had the genotype Med/ ‐α3.7, four the genotype –(a)20.5/–α3.7 and three the genotype Med/aαT. In one patient the restriction data are consistent with two possible genotypes aαT/αTor /aαT. It is demonstrated that HbH disease in Greece is heterogeneous, with the deletion haplotypes Med and –α3.7 being more prevalent than the ‐(a)20.5 and non‐deletion (ααT) haplotypes. Copyright © 1986, Wiley Blackwell. All rights reserve

The triplicated α gene locus and β thalassaemia

Summary. In five families, the coinheritance of β thalassaemia and an additional α gene (ααα/αα) has been observed. Among the β thalassaemia heterozygotes, no phenotypic effect of the triplicated α gene was detected clinically or at the haematological level. Unexpectedly, however, four out of five β thalassaemia homozygotes with the ααα/αα gene complement had the milder clinical condition of thalassaemia intermedia and in at least one case there was evidence to suggest that this might be due to the ααα gene arrangement acting as an α thalassaemia allele. Copyright © 1983, Wiley Blackwell. All rights reserve

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

Prevalence of β0 and β+ thalassemia genes in greek children with homozygous βthalassemia

In an attempt to estimate the prevalence of β0 and β+thalassemia genes in Greece chromatographic analysis of hemoglobins was performed in 30 children with homozygous βthalassemia prior to any transfusion. In 13 (43% no HbA was detected, suggesting the presence of β0 gene in the homozygous state (β0/β thal). In the remaining 17, HbA showed a bimodal distribution with values ranging from 4-36% The detection of HbA suggests the presence of β+ gene, while the bimodal distribution could be explained by the assumption that the β+ gene in single dose and in combination with β0 gene (β0/β+ thai) results in the production of small amounts of HbA ranging from 4-11% (first curve), while in double dose (β+/β+ thal), in the production of higher amounts of HbA ranging from 24-36% (second curve). The β0/β+ thai was observed in 11 (37% and the βplus;beta;+ thai in 6(20% It is concluded that both β0 and β+genes are common in Greece and chromatographic analysis helps to determine the genotype of patients with homozygous βthalassemia. © 1978 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted