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Potential pitfalls in the diagnosis of H b Handsworth in areas with high prevalence of H b S
Author(s) -
Al Zadjali S.,
AlRiyami A. Z.,
Gravell D.,
Al Haddabi H.,
Al Rawahi M.,
Al Falahi K.,
Daar S.
Publication year - 2014
Publication title -
international journal of laboratory hematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.705
H-Index - 55
eISSN - 1751-553X
pISSN - 1751-5521
DOI - 10.1111/ijlh.12157
Subject(s) - missense mutation , high performance liquid chromatography , globin , gene , microbiology and biotechnology , gel electrophoresis , cord blood , solubility , polyacrylamide gel electrophoresis , biology , mutation , genetics , chemistry , chromatography , biochemistry , enzyme , organic chemistry
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.