β‐thalassaemia carrier detection by ELISA: A simple screening strategy for developing countries

Abstract

The frequency of β‐thalassaemia in India ranges from 3.5% to 15% in the general population and of the 100,000 children born with thalassaemia major in the world, 10,000 are in India alone. Affected children do not die immediately, but treatment by regular transfusion is costly and leads to iron overload and death. Therefore, health services in lower‐economic countries can sustain patients only if the numbers can be limited. Detecting carrier couples by simple blood test can prevent thalassaemia and at‐risk couples can be identified and informed of their genetic risk before having children. A prevention programme including population screening, counselling, and prenatal diagnosis will markedly reduce the birth prevalence of affected individuals. Hemoglobin A₂ (HbA₂) measurement in human hemolysates has great significance, since its level can indicate β‐thalassaemia carrier status in otherwise healthy individuals. We have developed a rapid, simple, and inexpensive enzyme linked immunosorbent assay (ELISA) for the quantitation of HbA₂, which can be used in carrier screening programmes in developing countries like India. In a limited trial for β‐thalassaemia carrier screening, the results obtained with ELISAs were compared with those obtained with the microcolumn chromatography method (r=0.89). J. Clin. Lab. Anal. 19:22–25, 2005. © 2005 Wiley‐Liss, Inc.