Eight Cases of Hb Winnipeg [HBA2: c.226G>T (or HBA1)]: A Detailed Study

Abstract

Hb Winnipeg [α75(EF4)Asp→Tyr (α2); HBA2: c.226G>T (or HBA1)] is a stable α-globin chain variant described in a few articles. The majority of reported cases in older articles were clustered in Canada. It can occur on both α1- and α2-globin genes and in different populations. In this study, eight cases of Hb Winnipeg were characterized by DNA sequencing during a wide-spectrum study of suspected α-globin gene variants collected in the United Kingdom. All cases detected peaked in the S window between 4.4 and 4.54 min. on high performance liquid chromatography (HPLC). The isoelectric focusing (IEF) averaged at 6.21 below Hb A. All the mutations were detected on the α1-globin gene except in one case. The ethnic origin of the majority of the patients was Canadian. Only one case was associated with the common polymorphism HBA2: c.-24C>G (or HBA1) [Cap +14 (C>G)] on both α-globin genes without any apparent effect on the variant expression. All cases were detected in a heterozygous state. Hb Winnipeg expression was consistently lower than the theoretical value for α chain variants, ranging between 11.8 and 15.8% of total hemoglobin (Hb). This study gave more details about Hb Winnipeg that may help in presumptive diagnosis, especially in routine laboratories.

Keywords:

• α-Globin gene variants
• hemoglobin (Hb)
• Hb Winnipeg
• HBA1: c.-24C>G
• HBA2: c.-24C>G

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article. The views expressed in this publication are those of the authors and not necessarily those of the Department of Health.

Additional information

Funding

This study was supported by the European Commission grant for the project ‘eInfrastructure for Thalassaemia Research Network,’ Co-ordination Action, ITHANET [RI-2004–026539], and also by the Oxford Partnership Comprehensive Biomedical Research Centre with funding from the Department of Health’s National Institute of Health Biomedical Research Centre's funding scheme.