Spectrum of hemoglobin variants in Eastern Indian population; a study of 14,145 cases

Background: Inherited disorders of hemoglobin are extremely common in Indian population ranging from near structurally normal hemoglobins to severe transfusion dependant hemoglobinopathies. Their detection is important epidemiologically and to prevent other more serious hemoglobinopathies in future generations. Objectives: This is a retrospective study, where our objectives are to analyze the different hemoglobin (Hb) variants in West Bengal (WB) population and adjacent areas and to find out which particular district is at risk to which particular hemoglobinopathy. Materials & Methods: The study was done by BIORAD VARIANT using beta thalassemia (thal) short programme using high performance liquid chromatography (HPLC) technique. Complete hemogram of all the surgical and other patients were available before HPLC study. Cases were referred mostly by surgeons and clinicians either after getting abnormal hemogram or for premarital counseling. Results : Out of 14,145 cases 74.35% (10,518 cases) showed normal Hb pattern on HPLC and rest 26.65% (3627 cases) showed some abnormality. Common hemoglobinopathies included beta thal trait, E trait, E beta thal, persistent fetal Hb, thal major, thal minor, HbS trait. Other disorders were rare (<0.01%). Complete hemogram was done in all cases & anisopoikilocytosis, hypochromia, and abnormal RDW were found in majority of cases. MCV was generally normal to very low. District wise HbS and beta thal were more common in western part of West Bengal and HbE is more prevalent in central and north-east part of West Bengal. Conclusion: Abnormal hemoglobins as HbE and beta thal is very common in West Bengal. However many other Hb variants including mixed patterns are also found HPLC provides a rapid and accurate method to analyze these Hb variants and by quantifying HbA2 level prevents occurrence of more serious hemoglobinopathies in future generations.