Incidence of endocrine complications and clinical disease severity related to genotype analysis and iron overload in patients with β-thalassaemia

The incidence of endocrine dysfunction in relation to the detailed genotype of β-thalassaemia is investigated in this study. In addition, the association of genotype to specific clinical features of β-thalassaemia is examined, together with the relationship between serum ferritin levels and endocrine complications. Ninety-seven patients were included, all with transfusion dependent β-thalassaemia. Patients were divided into 2 categories; group 1 consisted of patients with a β 0 /β 0 genotype with or without a concomitant α-globin gene deletion as well as patients with β 0 /β + or β + /β + genotype and normal α-globin chain synthesis. Group 2 included patients with β + /β + or β + /β 0 genotype and one α-globin chain deletion and those with a moderate amount of β-globin chain synthesis (β ++ ) and normal α-globin chain synthesis. The results showed that group 1 patients were more likely to have severe clinical disease (p=0.005). Sixty-four patients (66%) had at least 1 endocrine disorder and 39 (40%) had multiple endocrinopathies; the most common abnormality was hypogonadotrophic hypogonadism (HH). There was a significant association between patients with group 1 genotypes and the presence of HH and impaired glucose tolerance or diabetes. A positive correlation was demonstrated between serum ferritin concentrations and the presence of thyroid or parathyroid dysfunction.