Hemoglobin, alpha 1

Hemoglobin, alpha 1, also known as HBA1, is a is_associated_with::hemoglobin protein that in humans is encoded by the HBA1 is_associated_with::gene.

Gene
The human alpha globin is_associated_with::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 (is_associated_with::HBA2) and alpha-1 (HBA1; this gene) coding sequences are identical. These genes differ slightly over the 5' untranslated regions and the is_associated_with::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 is_associated_with::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 is_associated_with::thalassemias result from deletions of each of the alpha genes as well as deletions of both is_associated_with::HBA2 and is_associated_with::HBA1; some nondeletion alpha thalassemias have also been reported.

Interactions
Hemoglobin, alpha 1 has been shown to interact with is_associated_with::HBB.