Is high pressure liquid chromatography an effective screening tool for characterization of molecular defects in hemoglobinopathies?

INTRODUCTION

Hemoglobinopathies constitute entities that are generated by either abnormal hemoglobin or thalassemias. high pressure liquid chromatography (HPLC) is one of the best methods for screening and detection of various hemoglobinopathies but it has intrinsic interpretive problems. The study was designed to evaluate the different mutations seen in cases of hemoglobinopathies and compare the same with screening tests.

MATERIALS AND METHODS

68 patients of hemoglobinopathies were screened by HPLC. Mutation studies in the beta globin gene was performed using the polymerase chain reaction (PCR)-based allele-specific Amplification Refractory Mutation System (ARMS). Molecular analysis for the sickle cell mutation was done by standard methods.

RESULTS

The IVS 1/5 mutation was the commonest mutation seen and it was seen in 26 (38.23%) of the cases. This was followed by the IVS 1/1, codon 41/42, codon 8/9, del 22 mutation, codon 15 mutation and the -619 bp deletion. No mutation was seen in eight cases. There was a 100% concordance between the sickle cell trait as diagnosed by HPLC and genetic testing.

DISCUSSION AND CONCLUSION

Our study underlies the importance of molecular testing in all cases of hemoglobinopathies. Although HPLC is a useful screening tool, molecular testing is very useful in accurately diagnosing the mutations. Molecular testing is especially applicable in cases with an abnormal hemoglobin (HbD, HbE and HbS) because there may be a concomitant inheritance of a beta thalassemia mutation. Molecular testing is the gold standard when it comes to the diagnosis of hemoglobinopathies.