hemoglobin, alpha 2 hemoglobin, alpha 2 hemoglobin, alpha 2 also known as hba2 is a gene that in humans codes for the alpha globin chain of hemoglobin. this article is about a gene. for the similarly named hemoglobin tetramer, hba2, see hemoglobin a2. hba2available structurespdbortholog search: pdbe rcsb list of pdb id codes1a00, 1a01, 1a0u, 1a0z, 1a3n, 1a3o, 1a9w, 1abw, 1aby, 1aj9, 1b86, 1bab, 1bbb, 1bij, 1buw, 1bz0, 1bz1, 1bzz, 1c7b, 1c7c, 1c7d, 1cls, 1cmy, 1coh, 1dke, 1dxt, 1dxu, 1dxv, 1fdh, 1fn3, 1g9v, 1gbu, 1gbv, 1gli, 1gzx, 1hab, 1hac, 1hba, 1hbb, 1hbs, 1hco, 1hdb, 1hga, 1hgb, 1hgc, 1hho, 1ird, 1j3y, 1j3z, 1j40, 1j41, 1j7s, 1j7w, 1j7y, 1jy7, 1k0y, 1k1k, 1kd2, 1lfl, 1lfq, 1lft, 1lfv, 1lfy, 1lfz, 1ljw, 1m9p, 1mko, 1nej, 1nih, 1nqp, 1o1i, 1o1j, 1o1k, 1o1l, 1o1m, 1o1n, 1o1o, 1o1p, 1qi8, 1qsh, 1qsi, 1qxd, 1qxe, 1r1x, 1r1y, 1rps, 1rq3, 1rq4, 1rqa, 1rvw, 1sdk, 1sdl, 1shr, 1si4, 1thb, 1uiw, 1vwt, 1xxt, 1xy0, 1xye, 1xz2, 1xz4, 1xz5, 1xz7, 1xzu, 1xzv, 1y01, 1y09, 1y0a, 1y0c, 1y0d, 1y0t, 1y0w, 1y22, 1y2z, 1y31, 1y35, 1y45, 1y46, 1y4b, 1y4f, 1y4g, 1y4p, 1y4q, 1y4r, 1y4v, 1y5f, 1y5j, 1y5k, 1y7c, 1y7d, 1y7g, 1y7z, 1y83, 1y85, 1y8w, 1ydz, 1ye0, 1ye1, 1ye2, 1yen, 1yeo, 1yeq, 1yeu, 1yev, 1yff, 1yg5, 1ygd, 1ygf, 1yh9, 1yhe, 1yhr, 1yie, 1yih, 1yvq, 1yvt, 1yzi, 1z8u, 2d5z, 2d60, 2dn1, 2dn2, 2dn3, 2dxm, 2h35, 2hbc, 2hbd, 2hbe, 2hbf, 2hbs, 2hco, 2hhd, 2hhe, 2m6z, 2w6v, 2w72, 2yrs, 3b75, 3d17, 3d7o, 3dut, 3hxn, 3ia3, 3ic0, 3ic2, 3kmf, 3nl7, 3nmm, 3odq, 3onz, 3oo4, 3oo5, 3ovu, 3p5q, 3qjb, 3qjc, 3qjd, 3qje, 3r5i, 3s48, 3s65, 3s66, 3szk, 3wcp, 3whm, 4fc3, 4hhb, 4ij2, 4l7y, 4m4a, 4m4b, 4mqc, 4mqg, 4mqh, 4mqi, 4mqj, 4mqk, 4n7n, 4n7o, 4n7p, 4n8t, 4ni0, 4ni1, 4rol, 4rom, 4wjg, 4x0l, 4xs0, 6hbw, 5e29, 5e6e, 5ee4, 5hu6, 5jdo, 5kdq, 5e83,%%s1y01, 1z8u, 1bz1identifiersaliaseshba2, hba-t2, hbh, hemoglobin, alpha 2, hemoglobin subunit alpha 2, ecyt7external idsomim: 141850 mgi: 96015 homologene: 469 genecards: hba2 gene location (human)chr.chromosome 16 (human)band16p13.3start172,876 bpend173,710 bpgene location (mouse)chr.chromosome 11 (mouse)band11 a4|11 18.86 cmstart32,233,511 bpend32,234,465 bprna expression patternbgeehumanmouse (ortholog)top expressed inmonocytebloodbone marrowbone marrow cellsplacentaspleenganglionic eminenceupper lobe of left lungamygdalasubstantia nigratop expressed inbone marrowspleenlungyolk sacneural tubemesencephalonheartcerebellar cortexzone of skinadrenal glandmore reference expression databiogpsn/agene ontologymolecular function iron ion binding oxygen binding peroxidase activity oxygen carrier activity metal ion binding protein binding heme binding haptoglobin binding organic acid binding cellular component cytosol endocytic vesicle lumen blood microparticle membrane extracellular region cytosolic small ribosomal subunit hemoglobin complex extracellular exosome haptoglobin-hemoglobin complex extracellular space biological process positive regulation of cell death protein heterooligomerization oxygen transport receptor-mediated endocytosis bicarbonate transport hydrogen peroxide catabolic process response to hydrogen peroxide cellular oxidant detoxification transport sources:amigo / quickgoorthologsspecieshumanmouseentrez304015122ensemblensg00000188536ensmusg00000069919uniprotp69905q91vb8refseq (mrna)nm_000517nm_008218refseq (protein)np_000508np_000508.1np_000549.1np_001077424location (ucsc)chr 16: 0.17 – 0.17 mbchr 11: 32.23 – 32.23 mbpubmed searchwikidataview/edit humanview/edit mouse function 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 hba1 (α1) 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 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 alpha-thalassemias most commonly result from deletions of any of the four alpha alleles, 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.