Genetic heterogeneity of β thalassemia in Western Sicily

In the present paper we examine the presence of the β thal. genotype in western Sicily and analyze its frequency. For this purpose we examined 32 patients, 9 of whom were effected by thalassemia major and 23 by thalassemia intermedia. Either β ⁺/β ⁺ or β ⁺/β ⁰ genotypes were always found in the first group, while in the second we found a number of quite heterogeneous genotypes; the patients from this group were divided into four subgroups: 1) homozygotes for β ⁺ with a high α/β ratio, 2) homozygotes for β ⁺ with a low α/β ratio; 3) homozygotes for δβ ⁰ or β ⁰ thalassemia intermedia; 4) double heterozygotes, e.g. δβ ⁺/β, δβ ⁰/β ⁺. The frequency of such genotypes is similar to that found by Schiliro et al. in eastern Sicily and by Kattamis et al. in Greece. It should be noted that for the first time in Sicily the presence of two cases of β ⁰ thalassemia intermedia is reported. We also report the frequency of the locus TAγ in the β thalassemia genotypes examined.