Publication Cover
Hemoglobin
international journal for hemoglobin research
Volume 39, 2015 - Issue 3
513
Views
15
CrossRef citations to date
0
Altmetric
Original Article

Interaction of an α-Globin Gene Triplication with β-Globin Gene Mutations in Iranian Patients with β-Thalassemia Intermedia

, , , , , , , , & show all
Pages 201-206 | Received 07 Aug 2013, Accepted 20 Jan 2015, Published online: 18 Jun 2015
 

Abstract

The 3.7 kb triplicated α-globin gene (αααanti 3.7) mutation has been found in most populations. It results from an unequal crossover between misaligned homologous segments in the α-globin gene cluster during meiosis. The pathophysiology and clinical severity of β-thalassemia (β-thal) are associated with the degree of α chain imbalance. The excess of α-globin chains plays an important role in the pathophysiology of β-thal. When heterozygous/homozygous β-thal coexists with an α gene numerical alteration, the clinical and hematological phenotype of thalassemia could change to mild anemia in case of an α deletion (−α/αα) or severe anemia in the case of an α triplication (αα/ααα). The coexistence of an αααanti 3.7 triplication is considered an important factor in the severity of β-thal, exacerbating the phenotypic severity of β-thal by causing more globin chain imbalance. This study shows that the αααanti 3.7 triplication is an important factor in the causation of β-thal intermedia (β-TI) in heterozygous β-thal.

This type of phenotype modification has rarely been observed and reported in the Iranian population. Here we report the coinheritance of a triplicated α-globin gene arrangement and heterozygous/homozygous β-thal in 23 cases, presenting with a β-TI or β-thal major (β-TM) phenotype. Some of these patients were considered to have a mild β-TI phenotype as they needed no blood transfusions; some occasionally received blood transfusions in their lifetime (for example on delivery) but some are dependent on regular blood transfusions (every 20 to 40 days). Our study was focused on the importance of detecting the α-globin gene triplication in genotype/phenotype prediction in Iranian thalassemia patients.

Acknowledgements

We thank all our colleagues at the Molecular Department of Kariminejad-Najmabadi Pathology and Genetics Center for valuable technical assistance and also appreciate the cooperation of all the patients who took part in this study.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.

Reprints and Corporate Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

To request a reprint or corporate permissions for this article, please click on the relevant link below:

Academic Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

Obtain permissions instantly via Rightslink by clicking on the button below:

If you are unable to obtain permissions via Rightslink, please complete and submit this Permissions form. For more information, please visit our Permissions help page.