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'. This gene has an ORF encoding a 141 aa polypeptide which is similar to the delta globins found in reptiles and birds. This locus was originally described as a pseudogene; however, it is currently thought to be a protein-coding gene. [provided by RefSeq, Jul 2008].