– Hemoglobin Subunit Zeta (HBZ) is a member of the Globin family. The zeta chain is an alpha-type chain of mammalian embryonic Hemoglobin that is synthesized primarily in the yolk sac of the early embryo, while alpha-globin is produced throughout fetal growth and adult life. The HBZ gene consists of five functional genes and two pseudogenes, the order of genes is 5-zeta-pseudozeta-mu-pseudoalpha-1-alpha-2-alpha-1-theta-1-3.