Association of an α-Globin Gene Cluster Duplication and Heterozygous β-Thalassemia in a Patient with a Severe Thalassemia Syndrome

Abstract

We describe a new case of a β-thalassemia (β-thal) heterozygote with the mutation IVS-II-654 (C>T) presenting with a transfusion-dependent phenotype. Multiplex ligation-dependent probe amplification (MLPA) and array comparative genomic hybridization (CGH) analyses of the α-globin gene cluster revealed a full duplication of the α-globin genes including the upstream regulatory element. The duplicated allele and the normal allele in trans resulted in a total of six active α-globin genes. The severe clinical phenotype seemed to be related to the considerable excess of the α- and β-globin deficit caused by the presence of the β-thal. α-Globin cluster duplication should be considered in patients heterozygous for β-thal who show a more severe phenotype than β-thal trait.

• α/β Ratio
• α-globin gene duplication
• β-thalassemia (β-thal)
• multiplex ligation-dependent probe amplification (MLPA)

Declaration of interest

This study was supported by grants from Natural Science (81100435) and Guangzhou Health Bureau (20121A021012), People’s Republic of China. The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.