Potential pitfalls in the diagnosis of H b Handsworth in areas with high prevalence of H b S

Summary Hb Handsworth is a rare α‐globin structural variant caused by a missense mutation either on the α2 or α1‐globin gene ( HBA2 or HBA1 : c.55G>C, p.Gly18Arg). This variant might be erroneously diagnosed as H b S unless secondary confirmative tests are carried out. We encountered a child with a prominent peak eluting in the ‘ S ’ window on high‐performance liquid chromatography ( HPLC ). Sickle solubility test, gel electrophoresis, and selective direct nucleotide sequencing of α1, α2, and β globin genes were performed on the patient's sample. In addition, previous HPLC results on a cord blood sample were retrieved. Sickle solubility test was negative. Gel electrophoresis revealed a band migrating at the S region with an extra faint band seen on acid gel electrophoresis. Molecular analysis of α2 globin gene revealed heterozygous state of H b H andsworth. Hb H andsworth is a rare variant that can mimic H b S on HPLC . Failure to recognize this rare variant in regions where H b S is highly prevalent may result in serious misdiagnosis and subsequent incorrect genetic counseling.