Spectrum of Haemoglobinopathies: A Hospital Based Study in Uttarakhand

Abstract

Introduction: Haemoglobinopathy is a worldwide inherited problem as recognized by WHO and care of affected patients incurs heavy expense on the limited resources of developing countries. There is a need for prevention of births of children with clinically significant haemoglobinopathies by population screening. Cation Exchange-High Performance Liquid Chromatography (CE-HPLC) has emerged to be a simple and precise method to quantify HbA2 , HbF and other variant haemoglobins with certain limitations. Most of the variant haemoglobins can be identified by their retention times, percentages and peak characteristics. Aim: The present study was undertaken to assess the prevalence and spectrum of various haemoglobinopathies in patients reporting to a tertiary health care centre in Uttarakhand, India. Materials and Methods: This was a prospective study conducted on 8144 samples. RBC indices were obtained by sysmex XP 100. CE-HPLC was performed on Biorad D10. The variant haemoglobins were identified on the basis of their percentages, retention times and peak characteristics. Peripheral blood film, reticulocyte count, HbH inclusion and sickling test were done in selected cases. Continuous variables were expressed as mean±SD. Categorical variables were expressed as percentages. Results: Antenatal population formed the bulk of the 8144 cases enrolled in this study. Haemoglobinopathy was seen in 5.9% of the cases with β thalassaemia trait being the commonest abnormality (2.82% of cases). HbD (Punjab) trait was the commonest variant haemoglobin encountered in the study population. There was a significant difference in percentages of variant fractions between compound heterozygotes and variant traits. A presumptive diagnosis of alpha thalassaemia trait was rendered based on RBC indices, iron profile and chromatogram study. Molecular studies were recommended in 81 cases with borderline increase in HbA2 levels to rule out silent mutations. Conclusion: A reasonably high frequency (5.9%) of haemoglobinopathies warrants a routine antenatal screening of total population. An accurate diagnosis can be made in majority of cases by haematological parameters, CE-HPLC chromatograms, cascade screening for haemoglobinopathies and spouses of antenatal cases positive for haemoglobinopathy.

Keywords

• beta thalassaemia trait
• haemoglobin variants
• high performance liquid chromatography