Letter to the Editor

Analysis of ^Gγ-158(C→T) polymorphism in hemoglobin E/β-thalassemia major in Southern China

Rong R Liu, Ming Y Wang and Yong R Lai^*

• * Corresponding author: Yong R Lai laiyongrong@hotmail.com

Author Affiliations

Department of Hematology, First Affiliated Hospital, Guangxi Medical University, China

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Journal of Hematology & Oncology 2010, 3:29 doi:10.1186/1756-8722-3-29

The electronic version of this article is the complete one and can be found online at: http://www.jhoonline.org/content/3/1/29

Received:	22 August 2010
Accepted:	7 September 2010
Published:	7 September 2010

© 2010 Liu et al; licensee BioMed Central Ltd.

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Background

The ^Gγ-158(C→T) polymorphism plays important function in the clinical variability of HbE/β-thalassemia. There is little known about ^Gγ-158(C→T) polymorphism in HbE/β-thalassemia major in Southern China. This study aimed to explore the association between HbE/β-thalassemia major and this polymorphism in Southern China.

Methods and Results

The frequency of the ^Gγ-158(C→T) polymorphism has been evaluated in 32 patients with HbE/β-thalassemia major from Southern China. Further analysis of the ^Gγ-158(C→T) polymorphism revealed the prominent frequency of this polymorphic pattern among HbE/β-thalassemia major patients (65.63%). The presence of this polymorphism was strongly correlated with the increase of HbF synthesis.

Conclusions

The frequency of the ^Gγ-158(C→T) polymorphism was relatively high in Southern Chinese patients with HbE/β-thalassemia major, often accompanying with high production of HbF. This feature appears to be different with reports in other races and regions.

To the Editor

Hemoglobin E/β-thalassemia(HbE/β-thalassemia) is a common form of severe thalassemia syndromes in the Southern Chinese provinces[1]. Clinical manifestations of these patients range from nearly asymptomatic to severe β-thalassemia disease. The ^Gγ-158(C→T) polymorphism (-158 Xmn I ^Gγ-globin polymorphism) has been shown to be associated with the increased production of HbF and can strongly influence this heterogeneity of HbE/β-thalassemia[1-6]. The condition of the -158 Xmn I ^Gγ-globin polymorphism has been rarely reported in HbE/β-thalassemia majors from Southern China. The present study was to investigate the frequency of the -158 Xmn I ^Gγ-globin polymorphism and its association with high HbF level in HbE/β-thalassemia major patients of the Southern Chinese.

The clinical data were collected from 32 patients with HbE/β-thalassemia major who were seen at the First Affiliated Hospital, GuangXi Medical University. We also collected data from and compared with 30 unrelated healthy individuals. Table 1 shows the existence of the -158 Xmn I ^Gγ-globin polymorphism among HbE/β-thalassemia major and healthy controls. The frequency of polymorphism in HbE/β-thalassemia major (65.63%) was significantly higher than those in healthy controls (P < 0.00). In these patients, there were 6 β-thalassemia mutations detected in trans to the βE-thalassemia mutation. None of α-thalassmeia and homozygote of the -158 Xmn I ^Gγ-globin polymorphism were found in all samples. Fig 1. displays the association between the -158 Xmn I ^Gγ-globin polymorphism and HbF level among the HbE/β-thalassemia major. The HbF level in Xmn I +/- group was more than that in Xmn I -/- group, confirming the significant difference between these two groups. The analysis by Spearman correlation indicated that the -158 Xmn I ^Gγ-globin polymorphism was associated with increased HbF systhesis (r_p = 0.588).

In HbE/β-thalassemia, particularly in the major cases, during hematopoietic stress, point mutation at G-gamma promoter (the -158 Xmn I ^Gγ-globin polymorphism) can induce high gamma chain production rate[7]. The heavy hematopoietic stress from severe anemia may thus leads to the high frequency of this polymorphism in Southern Chinese patients with HbE/β-thalassemia major. This is the first report of the frequency of the -158 Xmn I ^Gγ-globin polymorphism in patients with HbE/β-thalassemia major in Southern China. These data suggest that screening of the -158 Xmn I ^Gγ-globin polymorphism and HbF level in early childhood may help on the management of HbE/β-thalassemia major patients and possibly prevent severe complications in Southern China.

Acknowledgements

We are grateful to the investigators, Wei-Xiong Lin, and Yi-Dan Liang, Xuan Xiao for their technical assistance. This work was surported by grants from the National Natural Science Foundation of China (No. 30860307).

References