Identifying β-chain variants of hemoglobin: royal medical services experience

Abstract EN

Objective: β-chain Hemoglobin (Hb) variants are qualitative hereditary hemoglobinopathies that range clinically from silent carriers to transfusion-dependent anemia.

The aim of this study was to determine the frequency of β-chain Hb variants at the Jordanian Royal Medical Services.

Methods: The laboratory electronic records of hemoglobinopathy investigations for patients from different regions of Jordan during the period between 2008 to 2019 were retrospectively reviewed.

The tests were performed at Princess Iman Research and Laboratory Sciences Center and included complete blood counts and Bio-Rad Variant II High Performance Liquid Chromatography (HPLC) to detect and quantify normal and abnormal Hbs; Polymerase Chain Reaction (PCR)-based reverse dot blot hybridization (Vienna lab StripAssay) was used to detect the corresponding gene mutations behind the identified variants.

Results: Of the 31,700 samples investigated, 811 carried β-chain Hb variants.

HbS was identified in 690 (540 heterozygous, 150 homozygous), HbC in 53 (43 heterozygous and 10 homozygous), and HbE in 32 (all of which were heterozygous).

The corresponding mutations for HbS, HbC and HbE were identified on PCR.

The remaining 36 samples carried HbO Arab, HbD-Punjab, and Hb Lepore with counts of 20, 10 and 6, respectively; these were identified via the HPLC method.

Conclusion: HbS is the most common β-chain Hb variant in Jordon, followed by HbC then HbE.

HPLC and PCR are reliable methods for identification of such variants.

The current study enhances the knowledge of the hematologist into common Hb variants in our region, which can lead to better disease control, management, and prevention.

Abbreviations: Hb = Hemoglobin, HPLC = High Performance Liquid Chromatography, PCR = Polymerase Chain Reaction.