How many beta Hb chain genes are found in the human genome?

The human genome contains two beta globin (Hb) chain genes, which are essential components of hemoglobin responsible for oxygen transport in the blood. These genes are located on chromosome 11 within a cluster that includes several other related globin genes. The two beta globin genes are referred to as HBB, with one being the major beta globin gene and the other a duplicated gene that plays a role in the development of fetal hemoglobin. This biological arrangement is crucial for proper hemoglobin function, as it enables the body to produce different types of hemoglobin at various stages of development, including embryonic, fetal, and adult phases. Understanding this structure and function of beta globin genes is fundamental in the study of hematology and pediatric medicine, particularly in conditions like sickle cell disease and beta-thalassemia, which are linked to mutations in these genes.