Transcript What Is Thalassemia?

What Is Thalassemia?
 Thalassemia
is a group of inherited disorders of
hemoglobin synthesis characterized by a reduced or
absent output of one or more of the globin chains of
adult hemoglobin .
 The name is derived from the Greek words
Thalasso = Sea" and "Hemia = Blood" in reference
to anemia of the sea.
Reduction of α or β chain synthesis causes α or βthalassaemia respectively.
What Is Thalassemia?
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It is an inherited atuosomal recesive blood
disorder that causes mild or severe anemia .
The anemia is due to reduced hemoglobin and
fewer red blood cells than normal.
Hemoglobin is the protein in red blood cells
that carries oxygen to all parts of the body.
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In people with thalassemia, the genes
that code for hemoglobin are missing
or variant (different than the normal
genes). Severe forms of thalassemia
are usually diagnosed in early
childhood and are lifelong
conditions.
The two main types of thalassemia
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There are two types;
Alpha,  chain of Hgb I saffected, and
beta,  chain is affected (more common).
The genes for each type of thalassemia are
passed from parents to their children.
Alpha and beta thalassemias can be classified
into:
Mild (minor/trait),
Moderate (intermediate)
and severe (major forms.
Alpha thalassemia
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occurs when one or more of the four genes
needed for making the alpha globin chain of
hemoglobin are variant or missing. Moderate
to severe anemia results when more than two
genes are affected. The most severe form of
alpha thalassemia is known as alpha
thalassemia major (incompatible with life). It
can result in miscarriage.
Alpha Thalassemias
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Alpha thalassemia “silent carrier”
Mild alpha thalassemia, also called alpha
thalassemia minor or alpha thalassemia trait
Hemoglobin H disease
Hydrops fetalis, or alpha thalassemia major
Beta thalassemia
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occurs when one or both of the two genes
needed for making the beta globin chain of
hemoglobin are variant.
The severity of illness depends on whether one
or both genes are affected and the nature of the
abnormality. If both genes are affected, anemia
can range from moderate to severe. The severe
form of beta thalassemia is also known as
Cooley’s anemia. Cooley’s anemia is the most
common severe form of thalassemia
Transmission of ß thalassemia
If a carrier (thalassemia minor)
marries a non-carrier, on average
half of their children will be carriers,
but none will develop thalassemia
major.
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Transmission ß of thalassemia- Cont
However if two carriers marry, in
each pregnancy there is a 25%
chance of a non-carrier child, a 50%
chance of a carrier child
(thalassemia minor), and a 25%
chance of a child with thalassemia
major.
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An example of inheritance:
a carrier married to a normal person
Source: Emirates Thalassemia Society
abdullah ali alqarni
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An example of inheritance- Cont:
marriage between two carriers
Source: Emirates Thalassemia Society
abdullah ali alqarni
abdullah ali alqarni
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Types of ß thalassemia- Cont
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Thalassemia Intermedia.
Caused by the reduced availability of
beta chains in hemoglobin and
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Beta Thalassemias
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Beta thalassemia minor, also called
thalassemia minor or thalassemia trait.
Such people usually practice normal life, but
may suffer from a mild form of anemia.
Beta thalassemia intermedia, also called
thalassemia intermedia or mild Cooley’s
anemia . Can lead to moderate to severe
anemia and an array of complications
including bone deformities and splenomegaly.
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Beta thalassemia major, also called
thalassemia major or Cooley’s anemia
Mediterranean anemia
Cooley’s anemia is another name for the severe
form of beta thalassemia.
The name is sometimes used to refer to any
type of thalassemia that requires treatment
with regular blood transfusions.leading to ironoverload which is treated with chelation
therapy to prevent death from organ failure.
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If one gene is affected, a person is a carrier and
has mild anemia. This condition is called beta
thalassemia trait, or beta thalassemia minor.
If both genes are variant, a person may have
moderate anemia (beta thalassemia intermedia, or
mild Cooley’s anemia) or severe anemia (beta
thalassemia major, or Cooley’s anemia).
Cooley’s anemia, or beta thalassemia major, is a
rare condition. A survey in 1993 found 518
Cooley’s anemia patients in the United States.
Most of these persons had the severe form of the
illness, but there may be more who are not
diagnosed.
If two people with beta thalassemia trait (carriers) have a
baby, one of three things can happen:
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The baby could receive two normal genes (one from
each parent) and have normal blood (1 in 4 chance, or
25 percent).
The baby could receive one normal gene from one
parent and one variant gene from the other parent and
have thalassemia trait (2 in 4 chance, or 50 percent).
The baby could receive two thalassemia genes (one
from each parent) and have a moderate to severe form
of the disease (1 in 4 chance, or 25 percent).
What Are the Signs and Symptoms of
Thalassemia?
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The symptoms of thalassemia depend on the
type and severity of the disease. Symptoms
occur when not enough oxygen gets to various
parts of the body due to low hemoglobin and a
shortage of red blood cells in the blood
(anemia).
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“Silent carriers” and persons with alpha
thalassemia trait or beta thalassemia trait
(also called carriers) usually have no
symptoms. Those with alpha or beta
thalassemia trait often have mild anemia
that may be found by a blood test.
In more severe types of thalassemia, such as Cooley’s anemia,
signs of the severe anemia are seen in early childhood and
may include:
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Fatigue (feeling tired) and weakness
Pale skin or jaundice (yellowing of the skin)
Protruding abdomen, with enlarged spleen
and liver
Dark urine
Abnormal facial bones and poor growth
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Babies with all four genes affected (a condition
called alpha thalassemia major, or hydrops fetalis)
usually die before or shortly after birth
How Is Thalassemia Diagnosed?
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Thalassemia is diagnosed using blood tests, including a
complete blood count (CBC) and special hemoglobin
studies.
A CBC provides information about the amount of
hemoglobin and the different kinds of blood cells, such as
red blood cells, in a sample of blood. People with
thalassemia have fewer red blood cells than normal and
less hemoglobin than normal in their blood. Carriers of
the trait may have slightly small red blood cells as their
only sign.
Hemoglobin studies measure the types of hemoglobin in a
blood sample.
Cooley’s anemia
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is usually diagnosed in early childhood because of
signs and symptoms, including severe anemia.
Some people with milder forms of thalassemia may
be diagnosed after a routine blood test shows that
they have anemia. Doctors suspect thalassemia if a
child has anemia and is a member of an ethnic
group that is at risk for thalassemia.
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To distinguish anemia caused by iron deficiency
from anemia caused by thalassemia, tests of the
amount of iron in the blood may be done. Irondeficiency anemia occurs because the body doesn’t
have enough iron for making hemoglobin. The
anemia in thalassemia occurs not because of a lack
of iron, but because of a problem with either the
alpha globin chain or the beta globin chain of
hemoglobin. Iron supplements do nothing to
improve the anemia of thalassemia, because
missing iron is not the problem.
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Family genetic studies are also helpful in
diagnosing thalassemia. This involves
taking a family history and doing blood
tests on family members.
Prenatal testing can determine if an unborn
baby has thalassemia and how severe it is
likely to be.
How Is Thalassemia Treated?
Treatment for thalassemia depends on the type and severity
of the disease.
 People who are carriers (they have thalassemia trait)
usually have no symptoms and need no treatment.
 Those with moderate forms of thalassemia (for example,
thalassemia intermedia) may need blood transfusions
occasionally, such as when they are experiencing stress
due to an infection. If a person with thalassemia
intermedia worsens and needs regular transfusions, he or
she is no longer considered to have thalassemia
intermedia; instead, the person is said to have thalassemia
major, or Cooley’s anemia.
2-Iron Chelation Therapy
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Iron chelation therapy uses medicine to
remove the excess iron that builds up in the
body when a person has frequent blood
transfusions. If the iron is not removed, it
damages body organs, such as the heart and
liver.
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The medicine, deferoxamine (deh-fer-ROX-uhmeen), works best when given slowly under the
skin, usually with a small portable pump
overnight. This therapy is demanding and
sometimes is mildly painful, so some people
stop chelation therapy. A pill form of iron
chelation therapy, deferasirox, was approved in
November 2005 for use in the United States.
People who have iron overload should not take
vitamins or other supplements that contain iron.
3-Surgery
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Surgery may be needed if body organs, such as
the spleen or gall bladder, are affected. For
example, if the spleen becomes inflamed and
enlarged, it may be removed. If gallstones
develop, the gall bladder may be removed.
A-Bone Marrow or Stem Cell
Transplants
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Bone marrow or stem cell transplants have
been used successfully in some children with
severe thalassemia. This is a risky procedure,
but it offers a cure for those children who
qualify.
4-Other Treatments
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People with severe thalassemia are more likely
to get infections that can worsen their anemia.
They should get an annual flu shot and the
pneumonia vaccine to help prevent infections.
Folic acid is a B vitamin that helps build red
blood cells. People with thalassemia should
take folic acid supplements.
Researchers are also studying other treatments,
such as gene therapy and fetal hemoglobin.
5-Gene therapy
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Someday, it may be possible to cure
thalassemia in an unborn child by inserting a
normal gene into the child’s stem cells.
6-Fetal hemoglobin
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Researchers are studying ways to enhance
production of fetal hemoglobin in people with
thalassemia. Fetal hemoglobin is the type of
hemoglobin made by the body before birth. After
birth, the body usually switches from making fetal
hemoglobin to the adult form of hemoglobin. Some
children have a gene variant that prevents the
switch, and their continuing production of fetal
hemoglobin lessens the severity of their illness.
Researchers are testing ways to enhance fetal
hemoglobin production after birth.
How Can Thalassemia Be Prevented?
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Although thalassemia cannot be prevented,
it can be identified before birth by prenatal
diagnosis.
People who have or believe that they may
carry the thalassemia genes can receive
genetic counseling to avoid passing the
disorder to their children.
Living With Thalassemia
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The Cooley’s Anemia Foundation offers
support to people with various types of
thalassemia through its Thalassemia Action
Group.
If you have moderate or severe thalassemia,
you need to take care of your overall health.
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Follow your treatment plan. See your doctor regularly
for checkups and treatment.
If you must have regular blood transfusions and iron
chelation therapy, it is important to continue with
treatment as recommended.
If you have regular blood transfusions, you should
avoid taking vitamins or other supplements containing
iron.
Maintain a healthy diet. Your doctor may also give you
a supplement of folic acid (a B vitamin) every day to
help your body make new red blood cells.
Get a flu shot every year and the pneumococcal vaccine
to prevent infect
Key Points
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Thalassemia is an inherited blood disorder that
can cause mild to severe anemia.
Thalassemia involves problems with the
production of hemoglobin in red blood cells.
As a result, a person with thalassemia doesn’t
have enough hemoglobin or red blood cells to
carry oxygen throughout the body (anemia).
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Two main types of thalassemia are alpha and
beta thalassemia. Alpha thalassemia occurs
when there is a problem with the alpha globin
chain that is part of hemoglobin. Beta
thalassemia occurs when there is a problem with
the beta globin chain.
Mild, moderate, and severe forms of thalassemia
occur. Severe beta thalassemia is often called
Cooley’s anemia.
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The most common severe form of thalassemia
seen in the United States is beta thalassemia
major, or Cooley’s anemia. It mainly affects
people from Mediterranean countries and Asia.
Some people are “silent carriers” with no
symptoms. Other carriers have mild anemia but
usually need no treatment. Carriers can pass
thalassemia genes on to their children.
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Severe thalassemia is treated with frequent
blood transfusions and iron chelation
therapy to remove excess iron that builds up
in the body from the transfusions.
Bone marrow or stem cell transplants have
cured thalassemia in some children, but this
treatment is not available for most people
with thalassemia.
Researchers are studying new treatments,
including ways to cure thalassemia through
stem cell and gene therapies.
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