Rare Double Heterozygous of HbD/HbG in a Nigerian: A Case Report

Aim: To advocate the use of newer and improved methods towards accurate diagnosis of haemoglobinopathies

Case Presentation: A rare case of double heterozygous of HbD/G in a pregnant female Nigerian who had present to the antenatal clinic for routine Haemoglobin electrophoresis. She had previously been diagnosed as HbAS using capillary electrophoresis and HPLC techniques.

Discussion: Capillary zone electrophoretograms showed the presence of peaks in zone Hb A, Hb D, C and a small peak in Z1 zone. Bio-Rad D10 chromatogram also indicated the presence of four peaks which are identified as Hb A, Hb D, Hb G, and hybrid of HbD/HbG. A peak in Hb D zone of capillary electrophoresis was due to co-migration of Hb D and Hb G variants. The small peak in Z1 zone indicated the presence of alpha chain variant of HbG.

Conclusion: The case exemplifies the need to use more advanced methods, including DNA analysis in order to accurately diagnose haemoglobinopathies in the nation with the largest burden of sickle cell disease.