β° Thalassemia Trait in Sardinia

Abstract

The red cell indices and results of globin chain synthesis in peripheral blood of obligate β° thalassemia (β° thal) carriers (parents of hamozygous β° thal children) and β thalassemia (β thal) carriers identified during mass screening are reported. Red cell indices were similar in obligate β° carriers and in carriers diagnosed during mass screening. However there was a higher incidence of anemia in female obligate β° thal carriers. In Sardinia the β° thal carrier showed the usual hematological characteristics of the high Hb A₂ β thal carrier with microcytosis, hypochromia, reduced osmotic fragility: Hb F > 1% was found in 30% of the carriers. With MCV, MCH, osmotic fragility test (OFT) and Shine and Lal discriminant function we found 3.5%, 1.5%, 3.5% and 4.0% respectively false negatives in carrier identification. A part from one subject, all obligate carriers had elevated Hb A₂ levels. The α/β ratio in obligate carriers (mean±SD) was 1.83±0.26 (N=30).