title: Thalassemia Intermedia Caused by 16p13.3 Sectional Duplication in a β-Thalassemia Heterozygous Child.
abstract: Thalassemia intermedia is an inherited hemoglobin disorder characterized by a significant genetic and clinical heterogeneity. A wide spectrum of different genotypes-homozygous, heterozygous, and compound heterozygous-have been found to be responsible for it. The authors describe a Chinese child of β-thalassemia heterozygote with the mutation IVS2-654 (C→T) (HBB:c.316-197C→T) presenting with severe thalassemia intermedia. Multiplex ligation-dependent probe amplification (MLPA) and array comparative genomic hybridization (CGH) analyses of the α gene cluster revealed an approximate 146-kb duplication at 16p13.3 including the complete α gene cluster. The duplicated allele and the normal allele in trans result in a total of 6 active α genes. The severe clinical phenotype seemed to be related to the considerable excess of the α-globin and the β-globin deficit caused by the presence of the β-thalassemia. The α gene duplication should be considered in patients heterozygous for β-thalassemia who show a more severe phenotype than β-thalassemia trait.
authors.affiliation: Department of Hematology/Oncology, Guangzhou Women & Children Medical Center affiliated to Guangzhou Medical University , Guangzhou, Guangdong , China.
authors.forename: Sha
authors.initials: S
authors.lastname: Liu
authors.forename: Hua
authors.initials: H
authors.lastname: Jiang
authors.forename: Man-Yu
authors.initials: MY
authors.lastname: Wu
authors.forename: Yong-Ling
authors.initials: YL
authors.lastname: Zhang
authors.forename: Dong-Zhi
authors.initials: DZ
authors.lastname: Li
mesh_terms: D000483:Alleles; D044466:Asian People; D002675:Child, Preschool; D002869:Chromosome Aberrations; D002885:Chromosomes, Human, Pair 16 / Q000235:genetics*; D006579:Heterozygote; D006801:Humans; D008297:Male; D005810:Multigene Family; D055542:alpha-Globins / Q000235:genetics; D017086:beta-Thalassemia / Q000235:genetics*
chemical_list: D055542:alpha-Globins
keywords: CGH; MLPA; α-globin gene duplication; α/β ratio; β-thalassemia