View source for HBD

{{Short description|Mammalian protein found in Homo sapiens}}
{{other uses|HBD (disambiguation)}}
{{Infobox gene}}
'''Hemoglobin subunit delta''' is a [[protein]] that in [[human]]s is encoded by the ''HBD'' [[gene]].<ref name="pmid2649166">{{Cite journal |vauthors=Higgs DR, Vickers MA, Wilkie AO, Pretorius IM, Jarman AP, Weatherall DJ |date=May 1989 |title=A review of the molecular genetics of the human alpha-globin gene cluster |journal=Blood |volume=73 |issue=5 |pages=1081–104 |doi=10.1182/blood.V73.5.1081.1081 |pmid=2649166 |doi-access=free}}</ref>

== Function ==

The delta (HBD) and beta (HBB) genes are normally expressed in the adult: two alpha chains plus two beta chains constitute [[Hemoglobin A|HbA]], which in normal adult life comprises about 97% of the total hemoglobin. Two alpha chains plus two delta chains constitute [[Hemoglobin A2|HbA2]], which with [[Fetal hemoglobin|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' - [[HBE1|epsilon]] – [[HBG2|gamma-G]] – [[HBG1|gamma-A]] – '''delta''' – [[HBB|beta]] - 3'.<ref name="entrez" />

== Clinical significance ==

Mutations in the delta-globin gene are associated with [[Delta-thalassemia]].<ref name="entrez">{{Cite web |title=Entrez Gene: HBD hemoglobin, delta |url=https://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=3045}}</ref>

==See also==
* [[Hemoglobin]]
* [[Human β-globin locus]]
* [[Thalassemia]]

==References==
{{reflist}}

==Further reading==
{{refbegin}}
* {{Cite journal |vauthors=Schillirò G, Russo-Mancuso G, Dibenedetto SP, etal |year=1992 |title=Six rare hemoglobin variants found in Sicily. |journal=Hemoglobin |volume=15 |issue=5 |pages=431–7 |doi=10.3109/03630269108998862 |pmid=1802885}}
* {{Cite journal |vauthors=Collins FS, Weissman SM |year=1985 |title=The molecular genetics of human hemoglobin. |journal=Prog. Nucleic Acid Res. Mol. Biol. |series=Progress in Nucleic Acid Research and Molecular Biology |volume=31 |pages=315–462 |doi=10.1016/s0079-6603(08)60382-7 |isbn=9780125400312 |pmid=6397774}}
* {{Cite journal |vauthors=Giardina B, Messana I, Scatena R, Castagnola M |year=1995 |title=The multiple functions of hemoglobin. |journal=Crit. Rev. Biochem. Mol. Biol. |volume=30 |issue=3 |pages=165–96 |doi=10.3109/10409239509085142 |pmid=7555018}}
{{refend}}

{{PDB Gallery|geneid=3045}}
{{Hemeproteins}}

[[Category:Hemoglobins]]


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