Rare Hemoglobin Variant Hb Handsworth (HBA1:c.55 G>C): Leads to False Positive Diagnosis of Hb S

Hemoglobin Handsworth (HBA1: c.55 G>C) is a structural hemoglobin variant. This study examined the molecular and genetic characteristics of a proband and four family members using complete blood count (CBC), capillary electrophoresis (CE), PCR, and direct sequencing. In the capillary electrophoresis, the proband, father, and son all displayed an abnormal band for HbS. Direct sequencing revealed a heterozygous mutation at CD18 (GGC>CGC) in the HBA1 gene, confirming the presence of hemoglobin Hb Handsworth. It is important to note that individuals carrying only Hb Handsworth did not exhibit any abnormalities in the CBC, suggesting that Hb Handsworth is a non-pathological variation. However, the CE system cannot differentiate it from HbS, which can lead to misdiagnosis; thus, DNA sequencing is necessary for an accurate diagnosis.