Simultaneous PCR detection of β – thalassemia and α – thalassemia 1 (SEA type) in prenatal diagnosis of complex thalassemia syndrome

Objective: To establish a rapid PCR method for simultaneous detection of β-thalassemia and α-thalassemia 1 genes for diagnosis of complex αβ-thalassemia syndrome. Design and methods: Using multiplex allele specific PCR approach, we evaluated a simultaneous detection of the SEA type α-thalassemia 1 and the common Southeast Asian β-thalassemia and hemoglobin E genes. The system was tested on known cases of double heterozygote for α- and β-thalassemias and in a prenatal diagnosis of complex αβ-thalassemia syndrome. Results: Co-inheritance of α-thalassemia 1 (SEA type) with each of the common β-thalassemia genes in Southeast Asian and with hemoglobin E could be identified in a single PCR reaction. A successful application of this simultaneous detection system in prenatal diagnosis of a complex thalassemia syndrome caused by an EFBart’s disease was demonstrated in a Thai family. Conclusion: We have shown that correct diagnosis of double heterozygosity for α-thalassemia 1 and β-thalassemia or hemoglobin E could be obtained using a simultaneous multiplex PCR. These rapid PCR assays would facilitate characterization and prenatal diagnosis of complex thalassemia syndromes in the regions where both α- and β-thalassemias and hemoglobin E are common.