HbA2 and Fetal haemoglobin in the diagnosis of Thalassemia and Hemoglobinopathies

  • Sandhya Venkatachala Consultant Pathologist Apollo Hospitals Bangalore
  • Manjula Rajendran Assistant Professor Madurai medical college l
Keywords: Hemoglobin A2, Fetal haemoglobin, Hemoglobinopathy, Thalassemia, capillary electrophoresis


Background: Hemoglobin (Hb) disorders which include hemoglobinopathies and Thalassemia affect 7% of the world population. Capillary electrophoresis is useful  for screening and follow up of Hb disorders . Aim: To evaluate HbA2 and HbF (fetalhemoglobin) in the diagnosis of Thalassemia and hemoglobinopathies.Material and Methods : 100 consecutive Capillary Hemoglobin electrophoresis  done as a part of screening programme for Hb disorders from Jan2016 to june 2016 was included in the study. Children <1  yr of age and individuals with  recent blood transfusion were excluded  . Hb, RBC count and MCV were recorded.Results : Of the 100 Hb electrophoresis performed, 57 normal and 43 abnormal patterns were seen. Among the abnormal Hb patterns,   β thalassemia trait (βTT) was the most common constituting 58.2%   followed by Sickle cell (HbS) trait(11.7%), HbE trait(9.3%) and HbE/ β Thalassemia (7.0%). The HbA2 levels in normal, βTT, Sickle cell trait , HbE trait and HbE/ β thalassemia  were 2.12%(SD 0.5), 4.9%(SD 0.62), 3.28%(SD 0.43), 3.98%(SD 0.67) respectively . The difference in HbA2  were  significant (p value <0.0001).The difference in HbA2 levels between HbE trait  and HbE disease was also significant (p value 0.036).Based on the HbF levels Sickle cell hemoglobinopathy was  further classified. Conclusion: The difference in  HbA2 levels in normal subjects, Thalassemia and hemoglobinopathies are statistically significant. The percentage of HbF  in sickle cell  gives information about coexisting hemoglobin disorder. In HbEhemoglobinopathy, HbA2 along with HbF identifies a specific group HbE/ β Thalassemia which often needs clinical intervention.  DOI: 10.21276/APALM.1303

Author Biography

Sandhya Venkatachala, Consultant Pathologist Apollo Hospitals Bangalore
Consultant Pathologist


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Original Article