Coexistence of Hemoglobin D and Thalassemia Trait: A Rare Phenomenon with Cardiac Presentation.

Hemoglobin D (HbD) is a hemoglobin variant predominantly found in the northwestern regions of India, such as Punjab and Gujarat, as well as in Pakistan, Iran, and other countries. This variant results from a genetic mutation at the 121st amino acid residue, where glutamic acid is replaced by glutamine. HbD can occur in either homozygous or heterozygous forms. Individuals with HbD typically remain asymptomatic throughout their lives. Nonetheless, HbD can occasionally coexist with sickle cell disease, leading to clinical manifestations. The co-inheritance of HbD with thalassemia, though rare, is believed to present clinically, though such cases are scarcely documented in the literature. This article reports a case from the Bathinda district of Punjab involving a patient with coexisting HbD and thalassemia trait who presented with severe cardiac symptoms, potentially as a late consequence of hemoglobinopathy due to underlying chronic anemia. Additionally, we propose an algorithm designed to assist clinicians and diagnostic laboratory experts in the streamlined evaluation of hemoglobinopathies. This is particularly relevant given the limited availability and affordability of genetic allele testing in most clinical settings.