Transcript Anemia: Insufficient Erythrocytes

Dr Gihan Gawish
Anemia: Insufficient
Erythrocytes
• Hemorrhagic anemia – result of acute or
chronic loss of blood
• Hemolytic anemia – prematurely ruptured
RBCs
• Aplastic anemia – destruction or inhibition
of red bone marrow
Dr Gihan Gawish
Anemia: Decreased Hemoglobin
Content
Iron-deficiency anemia results from:
• A secondary result of hemorrhagic anemia
• Inadequate intake of iron-containing foods
• Impaired iron absorption
Pernicious anemia results from:
• Deficiency of vitamin B12
• Lack of intrinsic factor needed for absorption
of B12
• Treatment is intramuscular injection of
B12
Dr Gihan Gawish
Anemia: Abnormal Hemoglobin
• Thalassemias – absent or faulty globin chain in
Hb. RBCs are thin, delicate, and deficient in Hb
• Sickle-cell anemia – results from a defectiv gene
coding for an abnormal Hb called hemoglobin S
(HbS)
• HbS has a single amino acid substitution in the
beta chain
• This defect causes RBCs to become sickle
shaped in low oxygen situations
Dr Gihan Gawish
Thalassemias
Dr Gihan Gawish
Thalassemias
• Thalassemia is actually a group of inherited diseases of the blood
that affect a person's ability to produce hemoglobin, resulting in
anemia.
• Thalassemia, a genetic disease, can be mild or severe.
• Some carriers of the gene have no symptoms.
• It mainly affects people of Mediterranean or Asian ancestry.
•
It usually appears during the first two years of life.
• Severe thalassemia is treated with blood transfusions and treatment
to remove excess iron in the blood.
Dr Gihan Gawish
Thalassemias
• About 100,000 babies worldwide are born with severe forms of
thalassemia each year.
• Thalassemia occurs most frequently in people of Italian, Greek,
Middle Eastern, Southern Asian and African Ancestry.
• The two main types of thalassemia are called "alpha" and
"beta," depending on which part of an oxygen-carrying protein
in the red blood cells is lacking.
• Both types of thalassemia are inherited in the same manner.
Dr Gihan Gawish
Thalassemias
• The disease is passed to children by
parents who carry the mutated
thalassemia gene.
• A child who inherits one mutated
gene is a carrier, which is sometimes
called "thalassemia trait." Most
carriers lead completely normal,
healthy lives.
Dr Gihan Gawish
Thalassemias
• A child who inherits two thalassemia trait genes - one
from each parent - will have the disease.
• A child of two carriers has a 25 percent chance of
receiving two trait genes and developing the disease,
and a 50 percent chance of being a thalassemia trait
carrier.
Dr Gihan Gawish
Thalassemias
• Most individuals with alpha thalassemia have
milder forms of the disease, with varying
degrees of anemia.
• A child who inherits two copies of the mutated
gene for beta thalassemia will have beta
thalassemia disease.
• The child can have a mild form of the disease,
known as thalassemia intermedia, which causes
milder
anemia that rarely requires transfusions.
Dr Gihan
Gawish
Gene Therapy Offers Hope for a
Cure of Thalassemias
• Scientists are working to develop a gene therapy that may offer
a cure for thalassemia.
• Such a treatment might involve inserting a normal beta globin
gene (the gene that is abnormal in this disease) into the
patient's stem cells, the immature bone marrow cells that are
the precursors of all other cells in the blood.
• Another form of gene therapy could involve using drugs or other
methods to reactivate the patient's genes that produce fetal
hemoglobin - the form of hemoglobin found in fetuses and
newborns.
• Scientists hope that spurring production of fetal hemoglobin will
compensate for the patient's deficiency of adult hemoglobin.
Dr Gihan Gawish
Sickle-cell
anemia
Dr Gihan Gawish
Sickle-cell anemia
• Sickle cell anemia is a disease in which your body
produces abnormally shaped red blood cells.
• The cells are shaped like a crescent or sickle. They
don't last as long as normal, round red blood cells,
which leads to anemia.
• The sickle cells also get stuck in blood vessels, blocking
blood flow. This can cause pain and organ damage.
• A genetic problem causes sickle cell anemia. People
with the disease are born with two sickle cell genes, one
from each parent. If you only have one sickle cell gene,
it's called sickle cell trait.
•Dr Gihan
Most
states test newborn babies as part of their
Gawish
newborn screening programs.
What genes are related to sickle
cell disease?
• Mutations in the HBB gene cause sickle cell disease.
• The HBB gene provides instructions for making beta hemoglobin.
•
Various versions of beta hemoglobin result from different mutations
in the HBB gene.
• One particular HBB mutation produces an abnormal version of beta
hemoglobin known as hemoglobin S (HbS).
• Other mutations in the HBB gene lead to additional abnormal
versions of beta hemoglobin such as hemoglobin C (HbC) and
hemoglobin E (HbE).
• HBB mutations can also result in an unusually low level of betahemoglobin; this abnormality is called beta thalassemia.
Dr Gihan Gawish
Sickle-cell gene anemia
• In people with sickle cell disease, at least one of the beta
hemoglobin subunits in hemoglobin is replaced with hemoglobin S.
• In sickle cell anemia, which is a common form of sickle cell disease,
hemoglobin S replaces both beta hemoglobin subunits in
hemoglobin.
• In other types of sickle cell disease, just one beta hemoglobin
subunit in hemoglobin is replaced with hemoglobin S.
• The other beta hemoglobin subunit is replaced with a different
abnormal variant, such as hemoglobin C.
• For example, people with sickle-hemoglobin C (HbSC) disease have
hemoglobin molecules with hemoglobin S and hemoglobin C instead
of beta hemoglobin. If mutations that produce hemoglobin S and
beta thalassemia occur together, individuals have hemoglobin Sbeta thalassemia (HbSBetaThal) disease.
Dr Gihan Gawish
Sickle-cell gene anemia
• The sickle-shaped red blood cells die
prematurely, which can lead to anemia.
• Sometimes the inflexible, sickle-shaped
cells get stuck in small blood vessels and
can cause serious medical complications.
Dr Gihan Gawish
How do people inherit
sickle cell disease?
• This condition is inherited in an autosomal
recessive pattern, which means both copies of
the gene in each cell have mutations.
• The parents of an individual with an autosomal
recessive condition each carry one copy of the
mutated gene, but they typically do not show
signs and symptoms of the condition.
Dr Gihan Gawish
Polycythemia
•
Polycythemia – excess
increase blood viscosity
•
1.
2.
3.
Three main polycythemias are:
Polycythemia vera
Secondary polycythemia
Blood doping
Dr Gihan Gawish
RBCs
that