GSTM1 and thalassemia: This study reported four cases with compound heterozygous Hb C/Hb E without co-inherited α-thalassemia with Hb E levels ranging from 30.6 to 34.0%, while a compound heterozygous Hb C/Hb E co-inherited α0-thalassemia presented with Hb E levels of 35.6%.