Thalassemias
Thalassemias are a group of blood disorders that affect the way the
body makes hemoglobin, a protein found in red blood cells that is
responsible for carrying oxygen throughout the body.
The body contains more red blood cells than any other type of cell,
and each has a life span of about 4 months. Each day, the body produces
new red blood cells to replace those that die or are lost from the body.
With a thalassemia, the red blood cells are destroyed at a faster rate, leading to anemia a condition that can cause fatigue and other complications.
Thalassemias are inherited conditions — they're carried in the genes and passed on from parents to children. People who are carriers
of a thalassemia gene show no thalassemia symptoms and might not know
they're carriers. If both parents are carriers, they can pass the
disease to their kids. Thalassemias are not contagious.
While there are many different types of thalassemias, the main two are:
- Alpha thalassemia: when the body has a problem producing alpha globin
- Beta thalassemia : when the body has a problem producing beta globin
When the gene that controls the production of either of these
proteins is missing or mutated, it results in that type of thalassemia.
About Alpha Thalassemia
Alpha thalassemia occurs when the gene that controls the making of
alpha globins is absent or defective. It can be mild to severe and is
most commonly found in people of African, Middle Eastern, Chinese,
Southeast Asian, and, occasionally, Mediterranean descent.
Some children with alpha thalassemia have no symptoms and may
require no treatment. Others with more severe cases need regular blood
transfusions to treat anemia and other symptoms.
A child can only get alpha thalassemia by inheriting it from his or
her parents. Genes are "building blocks" that play an important role in
determining physical traits and many other things about us.
Humans are made up of trillions of cells that form the structure of
our bodies and carry out specialized jobs like taking nutrients from
food and turning them into energy. Red blood cells, which contain
hemoglobin, deliver oxygen to all parts of the body.
All cells have a nucleus at their center, which is kind of like the
brain or "command post" of the cell. The nucleus directs the cell,
telling it to grow, mature, divide, or die. The nucleus contains DNA
(deoxyribonucleic acid), a long, spiral-shaped molecule that stores the
genes that determine hair color, eye color, whether or not a person is
right- or left-handed, and many more traits. DNA, along with genes and
the information they contain, is passed down from parents to their
children during reproduction.
Each cell has many DNA molecules, but because cells are very small
and DNA molecules are long, the DNA is packaged very tightly in each
cell. These packages of DNA are called chromosomes, and each cell has
46 of them. Each package is arranged into 23 pairs — with one of each
pair coming from the mother and one from the father. When a child has
alpha thalassemia, there is a mutation in chromosome 16.
Alpha globin is made on chromosome 16. So, if any gene that tells
chromosome 16 to produce alpha globin is missing or mutated, less alpha
globin is made. This affects hemoglobin and decreases the ability of
red blood cells to transport oxygen around the body.
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