In the Asian samples, haemoglobin typing results showed that 10% of subjects had an abnormal haemoglobin type, 7 (4.8%) were beta-thalassaemia carriers, 5 (3.4%) were confirmed or suspected alpha-thalassaemia carriers, 2 (1.4%) were HbE carriers and 1 was Hb Constant-Spring carrier. This evidence concerns the gene GSTM1 and beta thalassemia.