HBD explained

Hemoglobin subunit delta is a protein that in humans is encoded by the HBD gene.^[1]

Function

The delta (HBD) and beta (HBB) genes are normally expressed in the adult: two alpha chains plus two beta chains constitute HbA, which in normal adult life comprises about 97% of the total hemoglobin. Two alpha chains plus two delta chains constitute HbA2, which with HbF comprises the remaining 3% of adult hemoglobin. Five beta-like globin genes are found within a 45 kb cluster on chromosome 11 in the following order: 5' - epsilon – gamma-G – gamma-A – delta – beta - 3'.

Clinical significance

Mutations in the delta-globin gene are associated with Delta-thalassemia.^[2]

See also

• Hemoglobin
• Human β-globin locus
• Thalassemia

Further reading

• Schillirò G, Russo-Mancuso G, Dibenedetto SP, etal . Six rare hemoglobin variants found in Sicily. . Hemoglobin . 15 . 5 . 431–7 . 1992 . 1802885 . 10.3109/03630269108998862 .
• Collins FS, Weissman SM . The molecular genetics of human hemoglobin. . Prog. Nucleic Acid Res. Mol. Biol. . Progress in Nucleic Acid Research and Molecular Biology . 31 . 315–462 . 1985 . 6397774 . 10.1016/s0079-6603(08)60382-7. 9780125400312 .
• Giardina B, Messana I, Scatena R, Castagnola M . The multiple functions of hemoglobin. . Crit. Rev. Biochem. Mol. Biol. . 30 . 3 . 165–96 . 1995 . 7555018 . 10.3109/10409239509085142 .

Notes and References

1. Higgs DR, Vickers MA, Wilkie AO, Pretorius IM, Jarman AP, Weatherall DJ . A review of the molecular genetics of the human alpha-globin gene cluster . Blood . 73 . 5 . 1081–104 . May 1989 . 2649166 . 10.1182/blood.V73.5.1081.1081. free .
2. Web site: Entrez Gene: HBD hemoglobin, delta.