HBA1, Official Symbol HBA1provided by HGNC Official Full Name hemoglobin subunit alpha 1provided by HGNC Primary source HGNC:HGNC:4823 See related Ensembl:ENSG00000206172 MIM:141800; AllianceGenome:HGNC:4823 Gene type protein coding RefSeq status REVIEWED Organism Homo sapiens Lineage Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae; Homo Also known as HBH; ECYT7; HBA-T3; METHBA Summary The human alpha globin gene cluster located on chromosome 16 spans about 30 kb and includes seven loci: 5'- zeta - pseudozeta - mu - pseudoalpha-1 - alpha-2 - alpha-1 - theta - 3'. The alpha-2 (HBA2) and alpha-1 (HBA1) 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. 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. Alpha thalassemias result from deletions of each of the alpha genes as well as deletions of both HBA2 and HBA1; some nondeletion alpha thalassemias have also been reported. [provided by RefSeq, Jul 2008] Annotation information Note: We are aware that there is inconsistency among GenBank, RefSeq, and other browsers about the gene order in the alpha globin cluster. According to review by staff at HbVar (http://globin.bx.psu.edu/hbvar/menu.html), the gene order, telomere to centromere, for these loci is ...HBZ(HBZ2)..HBZP(HBZ1)..HBA2..HBA1... [13 Feb 2013] Orthologs all