Study of Clinical, Hematological and Molecular Characteristics of Patients of Thalassemia and Hemoglobinopathies in Tertiary Care Hospital.

To study clinical, hematological and molecular characteristics of patients of thalassemia and hemoglobinopathies and to correlate the molecular characteristics with clinical and hematological presentations. Material: This observational cross sectional study included 100 patients of age >12 years of all genders with chronic haemolytic anemia and history of multiple blood transfusion. Blood and radiological investigations were done. Clinical, hematological and molecular characteristics were studied. Observation and Clinical: Pallor was present in all cases and icterus in 32% cases. Total 48% of the patients had hepatomegaly and 98% had splenomegaly. Among genotypes, 15% cases had α-thalassemia, 62% had β thalassemia + δβ thalassemia, 7% had HbS hemoglobinopathy, and 16% had HbE hemoglobinopathy. Hematological: Hemoglobin showed significant association with molecular genotypes of thalassemia with lowest being present in β-thalassemia + δβ thalassemia and HbE.MCV showed significant association with molecular genotypes, with HbE having the lowest MCV of 65.5 fl. LDH levels showed a significant association with molecular genotype with highest being in HbS hemoglobinopathy. Molecular Characteristics: Common mutations in compound α-thalassemia were 3.7, 4.2 and 20.5 deletion. As for β-thalassemia and δβ thalassemia, 47 cases had heterozygous type and 15 cases had homozygous types. In β-thalassemia, the homozygous type showed IVS1- 5(G→C),CD 41/42(→CTT) and IVSII-654(G→T) while heterozygous type showed CD16(→G), CD 41/42(→CTT), IVS1-5(G→C), and IVSII-654(G→T) . In δβ thalassemia, the heterozygous type showed δβ inversion mutation.In HbS hemoglobinopathy, heterozygous type showed Codon 6(A→T) and compound heterozygous type showed IVS1- 5(G→C) and Codon 6(A→T). In HbE hemoglobinopathy,the homozygous type showed CD26(G→A) and compound heterozygous type showed IVS1-5(G→C) and IVSII 654(G→T). Conclusion: The common thalassemia genotypes observed in our study were α-thalassemia (15%), β thalassemia + δβ thalassemia, (62%) HbS hemoglobinopathy (7%), and HbE hemoglobinopathy (16%). The patients presented with pallor, icterus, hepatomegaly, and splenomegaly which were comparable among all molecular genotypes of thalassemia and hemoglobinopathies. α-thalassemia had compound α-thalassemia with common mutations being 3.7, 4.2 and 20.5 deletion. As for β-thalassemia and δβ thalassemia, 47 cases had heterozygous type and 15 cases had homozygous types. In δβ thalassemia, the heterozygous type showed δβ inversion mutation in 5 cases. MCH, Retic count, ferritin stores, and peripheral blood smear were similar in all molecular genotypes. Hemoglobin, MCV and LDH showed a significant association with molecular genotypes. Microcytic hypochromic anaemia was commonest among all.The findings of the present study show that the genotypes of thalassemia are characterized by diversity as well as significant genetic heterogeneities.
(© Journal of the Association of Physicians of India 2011.)