Prevalence of β⁰ and β⁺ Thalassemia Genes in Greek Children with Homozygous β-Thalassemia

Abstract

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 β-thalassemia 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 β+/β⁺ 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 β-thalassemia.