IthaID: 1528

Also known as:

Comments: The deletion spans approximately 90 kb of DNA, removing the Aγ, δ, and β-globin genes. The 5' breakpoint is located about 116 bp usptream of the cap site of the Aγ-globin gene promoter and the 3' breakpoint is located about 66 kb downstream of the β-globin gene (~12.7 kb upstream of the 3' deletion breakpoint of the Chinese (Aγδβ)0-thalassemia [IthaID: 1527]). Carriers express 9%-17% of HbF, whereas homozygotes present with a mild anaemia. The 3' breakpoint occurs within a rearranged L1 sequence that normally occurs downstream of the β-globin gene. This could result in the juxtaposition of enhancer sequences in the vicinity of the Gγ globin gene.

We follow the HGVS sequence variant nomenclature and IUPAC standards.

Heterozygous records (preview in IthaPhen)

1. Zhang JW, Song WF, Zhao YJ, Wu GY, Qiu ZM, Wang FN, Chen SS, Stamatoyannopoulos G, Molecular characterization of a novel form of (A gamma delta beta)zero thalassemia deletion in a Chinese family., Blood, 81(6), 1624-9, 1993 PubMed
2. Zhang XQ, Zhang JW, The 3' breakpoint of the yunnanese (Agammadeltabeta)0-thalassemia deletion lies in an L1 family sequence: implications for the mechanism of deletion and the reactivation of the Ggamma-globin gene., Hum. Genet., 103(1), 90-5, 1998 PubMed