Uncovering the True Genotype: Unusually Severe Sickle Cell Disease in a Child with an Initial HbSC Diagnosis.

Sickle cell disease (SCD) is the most common genetic blood disorder worldwide. It encompasses a group of hemoglobinopathies caused by inheriting the sickle hemoglobin (HbS) gene, either in homozygous or heterozygous form. This results in variable clinical presentations and severity by genotype. HbSC is the most common compound heterozygous form and is generally mild, whereas HbSO-Arab, a rare hemoglobinopathy, is considered severe. Accurate diagnosis requires detection of HbS using at least two methods. This case describes an unusually severe course in a child initially diagnosed with HbSC but later confirmed to have HbSO-Arab.