Compound heterozygous delta beta thalassemia with IVS 1-5 (G>C) mutation presenting as thalassemia major phenotype
Keywords:GAP PCR, Leucocytoses, Thalassemia major
Delta beta thalassemia is an unusual variant of thalassemia with elevated level of fetal hemoglobin (HbF). Unlike beta thalassemia, delta beta thalassemia heterozygotes have milder phenotype and homozygotes present as thalassemia intermedia phenotype. We report a 11-month-old male child who presented with severe anemia, and hepatosplenomegaly, thalassemia major phenotype. On evaluation was diagnosed as compound heterozygous for δβ0/β thalassemia with IVS 1-5 (G>C) mutation. This case highlights the importance of genotyping of patients with δβ thalassemia and co-inheritance of δβ thalassemia deletion with point mutation for β-thalassemia results in severe clinical phenotype as thalassemia major.
Pandey H, Ranjan R, Singh K, Sharma A, Kishor K, Seth T et al. Contrasting co-inheritance of alpha and beta mutations in delta beta thalassemia and hereditary persistence of fetal hemoglobin: a study from India. Hematology. 2018;23(9):692-6.
Bollekens J, Forget B. δβ Thalassemia and hereditary persistence of fetal hemoglobin. Hematol Oncol Clin North Am. 1991;5(3):399-422.
Wood WG. Hereditary persistence of fetal hemoglobin and δβ-thalassemia. In: Steinberg MH, Forget BG, Higgs DR, Nagel RL, editor. Disorders of hemoglobin: genetics, pathophysiology, and clinical management. Cambridge: Cambridge University Press. 2001;356-88.
Nadkarni A, Wadia M, Gorakshakar A, Kiyama R, Colah RB, Mohanty D. Molecular characterization of delta beta-thalassemia and hereditary persistence of fetal hemoglobin in the Indian population. Hemoglobin. 2008;32:425-33.
Galanello R, Cao A. Relationship between genotype and phenotype; thalassemia intermedia. Ann NY Acad Sci. 1998;850:325-33.
Hariharan P, Kishnani P, Sawant P. Genotypic-phenotypic heterogeneity of δβ-thalassemia and hereditary persistence of fetal hemoglobin (HPFH) in India. Ann Hematol. 2020;99(7):1475-83.