Background: Interaction of α0-thalassemia and α+-thalassemia leads to the Hb H-disease and interaction of the Hb H-disease with Hb E leads to the AEBart’s disease. These thalassemia intermedia syndromes have diverse molecular heterogeneity and hematological phenotypes. In this study, we reported for the first time a genetic diversity associated with Hb H and AEBart’s diseases in Laos patients.
Materials and Methods: Study was done on Laos patients with Hb H disease (n=14) and AEBart’s disease (n=14), encountered at our Thalassemia Service Unit, CMDL, Khon Kaen University, Thailand. Their blood specimens were sent to our laboratory for investigation of anemia and thalassemia in a prevention and control program. Hematological parameters were recorded on standard blood cell counter. Hb analysis was done using capillary electrophoresis system (Capillarys II FP, Sebia). α- And β-globin genotypes were determined using PCR and related techniques.
Results: Hb and DNA analyses identified Hb H-disease resulted from [--SEA/-α3.7, bA/bA] (n = 7), [--THAI/-α3.7, bA/bA] (n = 1), Hb H-Constant Spring (CS) disease (--SEA/αCSα, bA/bA) (n = 5) and a previously undescribed Hb H-IVSI#117 (--SEA/α-IVSI#117G>A, bA/bA)(n = 1). For those of AEBart’s disease (n=14), 5 were found to be AEBart’s-CS disease [--SEA/ αCSα, bE/bA], 2 had [--THAI/ αCSα, bE/bA] genotype, 6 had AEBart’s disease with (--SEA/-α3.7, bE/bA) genotype and the remaining one was found to be a patient with AEBart’s-Pakse¢ [--SEA/ αPSα, bE/bA] disease (n = 1). Accurate diagnosis in most cases were obtained after DNA analysis.
Discussion and Conclusion: This study demonstrates the diverse heterogeneity and highlights the importance of molecular diagnosis of α-thalassemia diseases in Laos population. The data on molecular basis of α-thalassemia disease in Laos patients should prove useful for setting up a molecular diagnostic testing for thalassemia in Laos and further epidemiological study in the region.