Background: In area where hemoglobinopathies are prevalent, complex syndromes caused by interaction of globin gene defects may be encountered. We report a previously un-described of this syndrome.
Materials & Methods: Study was done in a Thai family in which the father was a patient with Hb Constant Spring EABart’s disease whereas the mother was a carrier of unknown α+-thalassemia. Their affected twin sons were suffered from severe transfusion dependent thalassemia. Rbc parameters were recorded and Hb analysis was done using capillary electrophoresis. α- And β-thalassemia mutations were examined.
Results: Both probands had severe anemia and received regular blood transfusion. Hb analysis revealed Hb A and unusually low Hb E, 3.8-7.3%. Hb analyses of the father identified Hb A, Hb E (13.7%), Hb CS (1.5%) and Hb Bart’s (0.5%) and Hb A and Hb A2 (2.5%) in the mother. Globin gene analysis identified α0-thalassemia (SEA) and Hb CS in the father, whereas the mother was negative for all common α-thalassemia found in Thailand. Further DNA analysis of the mother identified a (+T) insertion at codon 131/132 of α1 globin gene, corresponding to the Hb Pak Nam Po, described previously in a Thai Hb H disease. DNA analysis of both probands identified α0-thalassemia (SEA), Hb Pak Nam Po, and βE mutation in both cases.
Discussion and Conclusion: The two probands were affected by an unusual form of αβ-thalassemia syndrome, the Hb Pak Nam Po EABart’s disease, a hitherto undescribed condition. Identification of these cases confirms that in area where both thalassemia and hemoglobinopathies are prevalent and heterogeneous, complex syndromes may result from interaction of several defects with a spectrum of hematological and clinical manifestations. Accurate diagnosis of such cases using combined hematological testing and molecular analysis is required to understand the gene-gene interaction and improving genetic counselling.