Hemoglobin, alpha 2

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This article is about a gene. For the similarly named Hemoglobin tetramer, HbA2, see Hemoglobin A2.
Hemoglobin, alpha 2
PDB 1hbb EBI.jpg
PDB rendering based on 1hbb.
Available structures
PDB Ortholog search: PDBe, RCSB
Identifiers
Symbols HBA2 ; HBA-T2; HBH
External IDs OMIM141850 MGI96015 HomoloGene469 GeneCards: HBA2 Gene
Orthologs
Species Human Mouse
Entrez 3040 15122
Ensembl ENSG00000188536 ENSMUSG00000069919
UniProt P69905 P01942
RefSeq (mRNA) NM_000517 NM_008218
RefSeq (protein) NP_000508 NP_032244
Location (UCSC) Chr 16:
0.17 – 0.17 Mb
Chr 11:
32.28 – 32.28 Mb
PubMed search [1] [2]

Hemoglobin, alpha 2 also known as HBA2 is a gene that in humans codes for the alpha globin chain of hemoglobin.[1][2]

Function[edit]

The human alpha globin gene cluster is located on chromosome 16 and spans about 30 kb, including seven alpha like globin genes and pseudogenes: 5'- HBZ - HBZP1 - HBM - HBAP1 - HBA2 - HBA1 - HBQ1 -3'. The HBA2 (α2) and HBA11) coding sequences are identical. These genes differ slightly over the 5' untranslated regions and the introns, but they differ significantly over the 3' untranslated regions.

Protein[edit]

Two alpha chains plus two beta chains constitute HbA, which in normal adult life comprises about 97% of the total hemoglobin; alpha chains combine with delta chains to constitute HbA-2, which with HbF (fetal hemoglobin) makes up the remaining 3% of adult hemoglobin.

Clinical significance[edit]

Alpha-thalassemias most commonly result from deletions of any of the four alpha genes, although some alpha thalassemias have been reported that are due to mutations other than deletion. Deletion of 1 or 2 alleles is clinically silent. Deletion of 3 alleles causes HbH disease, resulting in anemia and hepatosplenomegaly. Deletion of all 4 alleles is lethal because it renders the body unable to make fetal hemoglobin (HbF), adult hemoglobin (HbA) or adult variant hemoglobin (HbA2), and results in hydrops fetalis. [3]

References[edit]

  1. ^ Liebhaber SA, Goossens MJ, Kan YW (Dec 1980). "Cloning and complete nucleotide sequence of human 5'-alpha-globin gene". Proceedings of the National Academy of Sciences of the United States of America 77 (12): 7054–8. doi:10.1073/pnas.77.12.7054. PMC 350439. PMID 6452630. 
  2. ^ Higgs DR, Vickers MA, Wilkie AO, Pretorius IM, Jarman AP, Weatherall DJ (Apr 1989). "A review of the molecular genetics of the human alpha-globin gene cluster". Blood 73 (5): 1081–104. PMID 2649166. 
  3. ^ "Entrez Gene: HBA2 hemoglobin, alpha 2". 

Further reading[edit]

  • Richter F, Meurers BH, Zhu C, Medvedeva VP, Chesselet MF (Aug 2009). "Neurons express hemoglobin alpha- and beta-chains in rat and human brains". The Journal of Comparative Neurology 515 (5): 538–47. doi:10.1002/cne.22062. PMC 3123135. PMID 19479992. 
  • Phylipsen M, Vogelaar IP, Schaap RA, Arkesteijn SG, Boxma GL, van Helden WC et al. (Aug 2010). "A new alpha(0)-thalassemia deletion found in a Dutch family (--(AW))". Blood Cells, Molecules & Diseases 45 (2): 133–5. doi:10.1016/j.bcmd.2010.05.004. PMID 20682466. 
  • Sessa R, Puzone S, Ammirabile M, Piscopo C, Pagano L, Colucci S et al. (Feb 2010). "Identification and molecular characterization of the --CAMPANIA deletion, a novel alpha (0) -thalassemic defect, in two unrelated Italian families [corrected]". American Journal of Hematology 85 (2): 143–4. doi:10.1002/ajh.21591. PMID 20054848. 
  • Yin XL, Zhang XH, Zhou TH, Zhang TL, Luo RG, Wang L et al. (2010). "Hemoglobin H disease in Guangxi province, Southern China: clinical review of 357 patients". Acta Haematologica 124 (2): 86–91. doi:10.1159/000314058. PMID 20639625. 
  • Joly P, Lacan P, Bererd M, Garcia C, Zanella-Cleon I, Becchi M et al. (2009). "Description of two new alpha variants: Hb Canuts [alpha85(F6)Asp-->His (alpha1)] and Hb Ambroise Pare [alpha117(GH5)Phe-->Ile (alpha2)]; two new beta variants: Hb Beaujolais [beta84(EF8)Thr-->Asn] and Hb Monplaisir [beta147 (Tyr-Lys-Leu-Ala-Phe-Phe-Leu-Leu-Ser-Asn-Phe-Tyr-158-COOH)] and one new delta variant: Hb (A2)North Africa [delta59(E3)Lys-->Met]". Hemoglobin 33 (3): 196–205. doi:10.1080/03630260903058685. PMID 19657833. 
  • Harteveld CL, Oosterhuis WP, Schoenmakers CH, Ananta H, Kos S, Bakker Verweij M et al. (Apr 2010). "alpha-thalassaemia masked by beta gene defects and a new polyadenylation site mutation on the alpha2-globin gene". European Journal of Haematology 84 (4): 354–8. doi:10.1111/j.1600-0609.2009.01380.x. PMID 19912309. 
  • Kapralov A, Vlasova II, Feng W, Maeda A, Walson K, Tyurin VA et al. (Oct 2009). "Peroxidase activity of hemoglobin-haptoglobin complexes: covalent aggregation and oxidative stress in plasma and macrophages". The Journal of Biological Chemistry 284 (44): 30395–407. doi:10.1074/jbc.M109.045567. PMC 2781594. PMID 19740759. 
  • Roy P, Bhattacharya G, Banerjee D, Chandra S, Ghosh M, Choudhuri U et al. (2009). "Hb Sallanches [alpha104(G11)Cys-->Tyr, TGC>TAC] occurs frequently on the Indian subcontinent". Hemoglobin 33 (6): 486–91. doi:10.3109/03630260903336164. PMID 19958194. 
  • Giardina B, Messana I, Scatena R, Castagnola M (1995). "The multiple functions of hemoglobin". Critical Reviews in Biochemistry and Molecular Biology 30 (3): 165–96. doi:10.3109/10409239509085142. PMID 7555018. 
  • Higgs DR, Vickers MA, Wilkie AO, Pretorius IM, Jarman AP, Weatherall DJ (Apr 1989). "A review of the molecular genetics of the human alpha-globin gene cluster". Blood 73 (5): 1081–104. PMID 2649166. 
  • Ribeiro DM, Sonati MF (2008). "Regulation of human alpha-globin gene expression and alpha-thalassemia". Genetics and Molecular Research 7 (4): 1045–53. doi:10.4238/vol7-4gmr472. PMID 19048483. 
  • Waye JS, Eng B, Dutly F, Frischknecht H (2009). "alpha-Thalassemia caused by two novel splice mutations of the alpha2-globin gene: IVS-I-1 (G>A and G>T)". Hemoglobin 33 (6): 519–22. doi:10.3109/03630260903333377. PMID 19958200. 
  • Coelho A, Picanço I, Seuanes F, Seixas MT, Faustino P (Aug 2010). "Novel large deletions in the human alpha-globin gene cluster: Clarifying the HS-40 long-range regulatory role in the native chromosome environment". Blood Cells, Molecules & Diseases 45 (2): 147–53. doi:10.1016/j.bcmd.2010.05.010. PMID 20580289. 
  • Sharma V, Kumar B, Kumar G, Saxena R (Oct 2009). "Alpha globin gene numbers: an important modifier of HbE/beta thalassemia". Hematology 14 (5): 297–300. doi:10.1179/102453309X446126. PMID 19843387. 
  • Turbpaiboon C, Wilairat P (2010). "Alpha-hemoglobin stabilizing protein: molecular function and clinical correlation". Frontiers in Bioscience 15: 1–11. doi:10.2741/3601. PMID 20036801. 
  • Voon HP, Vadolas J (Dec 2008). "Controlling alpha-globin: a review of alpha-globin expression and its impact on beta-thalassemia". Haematologica 93 (12): 1868–76. doi:10.3324/haematol.13490. PMID 18768527. 
  • Giordano PC, Cnossen MH, Joosten AM, Jansen CA, Hakvoort TE, Bakker-Verweij M et al. (2010). "Codon 24 (TAT>TAG) and codon 32 (ATG>AGG) (Hb Rotterdam): two novel alpha2 gene mutations associated with mild alpha-thalassemia found in the same family after newborn screening". Hemoglobin 34 (4): 354–65. doi:10.3109/03630269.2010.486341. PMID 20642333. 
  • Mahdavi MR, Kowsarian M, Karami H, Mohseni A, Vahidshahi K, Roshan P et al. (Oct 2010). "Prevalence of hemoglobin alpha-chain gene deletion in neonates in North of Iran". European Review for Medical and Pharmacological Sciences 14 (10): 871–5. PMID 21222374. 
  • Balakrishnan G, Zhao X, Podstawska E, Proniewicz LM, Kincaid JR, Spiro TG (Apr 2009). "Subunit-selective interrogation of CO recombination in carbonmonoxy hemoglobin by isotope-edited time-resolved resonance Raman spectroscopy". Biochemistry 48 (14): 3120–6. doi:10.1021/bi802190f. PMC 2722936. PMID 19245215. 
  • Zhu C, Yu W, Xie J, Chen L, Ding H, Shang X et al. (Oct 2010). "Hemoglobin H disease due to a de novo mutation at the α2-globin gene and an inherited common α-thalassemia deletion found in a Chinese boy". Blood Cells, Molecules & Diseases 45 (3): 223–6. doi:10.1016/j.bcmd.2010.07.005. PMID 20691621. 

External links[edit]

This article incorporates text from the United States National Library of Medicine, which is in the public domain.