Hemoglobin E disease in North Indian population: a report of 11 cases.

Hemoglobin E (beta26Glu --> Lys) is the most common hemoglobin (Hb) variant in Southeast Asia and the second most prevalent worldwide. However in India, it is prevalent in Bengal and the north-eastern region, but relatively rare in the rest of the country. Identification of this Hb variant is important, because the doubly heterozygous state for HbE and beta-thalassemia is characterized clinically by thalassemia major, a situation different from other compound heterozygous states for structural beta-chain variants and beta-thalassemia. Thus, the affected individual may be symptomatic and transfusion dependent at an early age. This paper reports four cases with Hb E trait, three cases with hemoglobin E disease and another four cases with Ebeta-thalassemia. Laboratory investigations are based on RBC indices and high performance liquid chromatography (HPLC). A negative correlation has been found to exist between levels of HbA(2) and RBC indices including the MCV and MCH. A similar correlation has been seen between levels of HbF with Hb, RBC count, and MCV. The main aim is to increase the awareness of this relatively rare disorder, so that it can be included in the differential diagnosis of patients presenting clinically like thalassemia intermedia or thalassemia major. This awareness may also help in prenatal diagnosis, genetic counseling and clinical management. The clinical, hematological and laboratory features of this disorder are also discussed.