Hemoglobin N Seattle in a Bengali Child: Diagnostic Challenges and Insights into Genetic Diversity – A Case

Background: Hemoglobin N Seattle is an exceedingly rare hemoglobin variant characterized by a lysine-to-glutamic acid substitution at position 61 of the beta-globin chain. While primarily reported in individuals of African and mixed ethnic origins, its occurrence in the Bengali population remains undocumented. Case Presentation: A 1-year, 6-month, and 24-day-old male child presented with poor appetite, frequent respiratory infections, and anemia at Anower Khan Modern Medical College and Hospital, Bangladesh. Initial complete blood count revealed Hb 9.4 g/dL, MCV 64.2 fL, and MCH 18.1 pg. Capillary zone electrophoresis (CZE) demonstrated reduced levels of Hb A (69.0%), Hb A2 (1.6%), and an abnormal peak (29.2%) in Zone 14. High-performance liquid chromatography (HPLC) identified a significant peak (27.4%) in the labile A1c window, indicative of Hb N Seattle. Genetic analysis confirmed the presence of the Hb N Seattle variant in the child’s mother, while the father exhibited normal findings. Both mother and child were asymptomatic for diabetes, distinguishing this case from previous reports. Conclusions: This case represents the first documented occurrence of Hb N Seattle in the Bengali population, expanding our understanding of its geographic distribution. The findings underscore the value of advanced diagnostics, including CZE, HPLC, and genetic analysis, in identifying rare hemoglobin variants. Comprehensive family screening and genetic counseling are recommended for accurate diagnosis and management.