title: 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.
authors.affiliation: Department of Hematology/Oncology, Guangzhou Women & Children Medical Center affiliated to Guangzhou Medical University , Guangzhou, Guangdong , People's Republic of China and.
authors.forename: Hua
authors.initials: H
authors.lastname: Jiang
authors.forename: Sha
authors.initials: S
authors.lastname: Liu
authors.forename: Yong-Ling
authors.initials: YL
authors.lastname: Zhang
authors.forename: Jun-Hui
authors.initials: JH
authors.lastname: Wan
authors.forename: Ru
authors.initials: R
authors.lastname: Li
authors.forename: Dong-Zhi
authors.initials: DZ
authors.lastname: Li
mesh_terms: D002648:Child; D002885:Chromosomes, Human, Pair 16; D055028:Comparative Genomic Hybridization; D056915:DNA Copy Number Variations; D004909:Erythrocyte Indices; D005260:Female; D020440:Gene Duplication; D006579:Heterozygote; D006801:Humans; D007438:Introns; D005810:Multigene Family; D009154:Mutation; D012720:Severity of Illness Index; D013577:Syndrome; D013789:Thalassemia / Q000175:diagnosis* / Q000235:genetics*; D055542:alpha-Globins / Q000235:genetics*; D055544:beta-Globins / Q000235:genetics*; D017086:beta-Thalassemia / Q000235:genetics*
chemical_list: D055542:alpha-Globins; D055544:beta-Globins
keywords: multiplex ligation-dependent probe amplification (MLPA); α-globin gene duplication; α/β Ratio; β-thalassemia (β-thal)