Studies on Haemoglobin E β-thalassaemia in Sri Lanka

Abstract

Haemoglobin E β-thalassaemia is the commonest cause of non-transfusion dependent thalassaemia in Sri Lanka. It is a disease exclusively restricted to people of South and Southeast Asian descent. It is phenotypically very variable, presenting great difficulties in the establishment of management guidelines. A cohort of patients with this disease has been followed up at the Kurunegala Thalassaemia Centre for nearly 20 years, in an attempt to study the basis for the enormous phenotypic diversity. All were initially taken off transfusion and observed closely for their response. Patients were classed into five groups based on growth and clinical responses, and further laboratory studies were done in an attempt to explain the reasons for observed variations. Primary, secondary and tertiary modifiers involved in phenotype modification were identified, along with some clinical factors which may predict disease severity. Older patients were observed to have lower markers of bone marrow expansion.