The beta globin (HBB) gene maps in the short arm of
chromosome 11
in a region also containing the delta globin gene, the embryonic epsilon gene, the fetal A-gamma and G-gamma genes, and a pseudogene (ψB1). The five functional globin genes are arranged in the order of their developmental expression (Fig. 2).
What chromosome is the alpha globin genes located on?
The HBA1 gene provides instructions for making a protein called alpha-globin. This protein is also produced from a nearly identical gene called HBA2. These two alpha-globin genes are located close together in a region of
chromosome 16
known as the alpha-globin locus.
Where is beta-globin gene located?
The β-globin gene cluster occupies a
region of approximately 17 kb on the short arm of chromosome 11
. Each of its constituent genes, their flanking regions, and large stretches of the regions between them have been sequenced.
On which chromosome is the hemoglobin beta gene HBB gene located?
HBB protein is produced by the gene HBB which is located in the multigene locus of β-globin locus on
chromosome 11
, specifically on the short arm position 15.4.
Which human chromosome contains the beta hemoglobin gene?
The human β-globin locus is composed of five genes located on a short region of
chromosome 11
, responsible for the creation of the beta parts (roughly half) of the oxygen transport protein Haemoglobin.
What is the function of beta globin?
The beta globin protein is one of the subunits of hemoglobin, a protein necessary for
the oxygen-carrying function of red blood cells
. People with the sickle cell mutation in both copies of the HBB gene produce proteins that clump together and lead to changes in the shape and behavior of red blood cells.
What is the most common hemoglobinopathy?
Sickle cell disease
, the most common hemoglobinopathy, occurs when at least one HbS variant is present with a second pathogenic beta globin variant; the variants result in abnormal Hb. For more information on pathogenic Hb variants, see the Human Hemoglobin Variants and Thalassemias database.
Which thalassemia is most common?
Beta
thalassemia
is a fairly
common
blood disorder worldwide. Thousands of infants with beta
thalassemia
are born each year. Beta
thalassemia
occurs
most frequently
in people from Mediterranean countries, North Africa, the Middle East, India, Central Asia, and Southeast Asia.
Can thalassemia be cured?
Bone marrow and stem cell transplant from a compatible related donor
is the only treatment that can cure thalassemia. It is the most effective treatment.
Which chromosome carries the mutated gene causing beta thalassemia?
The hemoglobin beta gene (HBB) encodes the β-chain and is located on
chromosome 11
. In α-thalassemia, there is deficient synthesis of α-chains. The resulting excess of β-chains bind oxygen poorly, leading to a low concentration of oxygen in tissues (hypoxemia).
Is Sickle Cell Anemia a substitution mutation?
Sickle cell anemia results from the
single amino acid substitution of valine
for glutamic acid in the beta-chain owing to a nucleotide defect that causes the production of abnormal beta-chains in hemoglobin S.
What chromosome is sickle cell disease on?
Sickle cell disease is caused by a mutation in the hemoglobin-Beta gene found on
chromosome 11
. Hemoglobin transports oxygen from the lungs to other parts of the body. Red blood cells with normal hemoglobin (hemoglobin-A) are smooth and round and glide through blood vessels.
How many globin genes are there?
Since each cell has two chromosomes 16, a total of
four alpha globin genes
exist in each cell. Each of the four genes produces about one-quarter of the alpha globin chains needed for hemoglobin synthesis.
Is hemoglobin conserved?
The tertiary structures of human hemoglobin (α chain), human myoglobin, and lupine leghemoglobin
are conserved
. Each heme group contains an iron atom to which oxygen binds. Anyone aware of the similar biochemical functions of hemoglobin, myoglobin, and leghemoglobin could expect the structural similarities.
How is the hemoglobin gene expressed?
Hemoglobin gene expression is restricted to erythroid cells. The genes are expressed
at extremely high levels late in erythroid differentiation
, with balanced production of α-globin and β-globin. Paralogous globin genes are expressed at progressive developmental stages.
What is the origin of hemoglobin?
hemoglobin (n.)
also hæmoglobin, coloring matter in red blood cells, 1862, shortening of hæmatoglobin (1845),
from Greek haimato-
, combining form of haima (genitive haimatos) “blood” (see -emia) + globulin, a type of simple protein, from globule, formerly a word for “corpuscle of blood.”
