IthaID: 1505

Names and Sequences

Functionality: Globin gene causative mutation Pathogenicity: N/A
Common Name: South East Asian (SEA) deletion HGVS Name: NC_000011.10:g.5201647_5229059del
Hb Name: N/A Protein Info: N/A

Also known as: Vietnamese, SE Asian, HPFH-7, SEA-HPFH, 27 kb deletion

Comments: The deletion comprises the entire β-globin gene with a total deletion length of 27 kb, resulting of a non-homologous recombination event. In the first time reported as Vietnamese HPFH deletion with approximate size of 30 kb [PMID 7689901]. The 5′ breakpoint is located ~3.5 kb downstream of the δ-globin gene, while the 3' breakpoint is located ~2.3 kb downstream from the 3′ HS-1 site (γ-silencing element) of the β-globin gene. Recent studies determined the exact breakpoints of the deletion and patients haematological indices (microcytosis and increased Hb A2) indicated that the SEA deletion is more akin to a β-thal phenotype with raised HbF, because of the deletion of γ-silencing element.

We follow the HGVS sequence variant nomenclature and IUPAC standards.

External Links


Hemoglobinopathy Group: Thalassaemia
Hemoglobinopathy Subgroup: β-thalassaemia
Allele Phenotype:N/A
Associated Phenotypes: Hb F levels [HP:0011904] [OMIM:141749]


Chromosome: 11
Locus: NG_000007.3
Locus Location: 68557
Size: 27.412 kb
Deletion involves: β

Other details

Type of Mutation: Deletion
Ethnic Origin: Vietnamese, Cambodian, Chinese Zhuang
Molecular mechanism: N/A
Inheritance: Recessive
DNA Breakpoint Determined: Yes

In silico pathogenicity prediction

Sequence Viewer

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Publications / Origin

  1. Motum PI, Hamilton TJ, Lindeman R, Le H, Trent RJ, Molecular characterisation of Vietnamese HPFH., Human mutation, 2(3), 179-84, 1993 PubMed
  2. Dimovski AJ, Divoky V, Adekile AD, Baysal E, Wilson JB, Prior JF, Raven JL, Huisman TH, A novel deletion of approximately 27 kb including the beta-globin gene and the locus control region 3'HS-1 regulatory sequence: beta zero-thalassemia or hereditary persistence of fetal hemoglobin?, Blood, 83(3), 822-7, 1994 PubMed
  3. Xu XM, Li ZQ, Liu ZY, Zhong XL, Zhao YZ, Mo QH, Molecular characterization and PCR detection of a deletional HPFH: application to rapid prenatal diagnosis for compound heterozygotes of this defect with beta-thalassemia in a Chinese family., Am. J. Hematol., 65(3), 183-8, 2000 PubMed
  4. So CC, So AC, Chan AY, Tsang ST, Ma ES, Chan LC, Detection and characterisation of beta-globin gene cluster deletions in Chinese using multiplex ligation-dependent probe amplification., J Clin Pathol, 62(12), 1107-11, 2009 PubMed
  5. Cai WJ, Li J, Xie XM, Li DZ, Screening for common β-globin gene cluster deletions in Chinese individuals with increased hemoglobin F., Int J Lab Hematol, 37(6), 752-7, 2015 PubMed
  6. He S, Wei Y, Lin L, Chen Q, Yi S, Zuo Y, Wei H, Zheng C, Chen B, Qiu X, The prevalence and molecular characterization of (δβ)(0) -thalassemia and hereditary persistence of fetal hemoglobin in the Chinese Zhuang population., J. Clin. Lab. Anal. , 2017 PubMed
Created on 2010-06-16 16:13:17, Last reviewed on 2022-02-02 11:03:24 (Show full history)

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