The diagnostic dilemma of congenital unstable hemoglobinopathies.

Unstable hemoglobin variants represent a rare etiology of congenital hemolytic anemia. Without a high index of suspicion, plus proper laboratory testing and interpretation, the correct diagnosis can be elusive. We report on five children who were initially thought to have other congenital disorders such as hereditary spherocytosis or thalassemia, before β-globin gene sequencing led to the definitive diagnosis. Recognizing the variable clinical presentation and laboratory data reported will aid clinicians in diagnosis of unstable hemoglobins variants in children with atypical forms of hemolytic anemia, particularly those with low pulse oximetry values or whose hemoglobin electrophoresis suggest β-thalassemia trait.