12 thalassaemic patients from Northern Sardinia showing the β+ phenotype were examined by isoelectric focusing and high-performance liquid chromatography techniques for the determination of the variant AγT globin chain of the foetal haemoglobin. Two patients (16.7%) were homozygotes for the AγT gene variant, 2 (16.7%) were heterozygotes and 8 (66.7%) were homozygotes for the normal AγT allele. The AγT gene frequency was 0.183, much lower than the observed 0.823 in β° homozygosity. These data suggest the presence of at least 2 β+ -thalassaemic chromosomes in Sardinians, one associated with the variant AγT allele and one associated with the normal AγI. The latter is prevalent among adult patients showing the intermediate form of the thalassaemic disease, which is not transfusion-dependent.