Sickle cell anemia is a genetic blood disorder where red blood cells become rigid and sickle-shaped. It is caused by a mutation in the hemoglobin gene. Symptoms include anemia, episodes of pain, frequent infections, and potentially serious complications affecting organs and tissues. Diagnosis is made via a blood test. Treatment focuses on pain management, antibiotics, hydroxyurea, blood transfusions, and potentially a bone marrow transplant to cure the disease.

2. MUHAMMAD IMRAN SIDDIQUE
S1F17BSZL0095
CLASS:- BS(H)ZOOLOGY (VI)
COURSE:- GENETICS
TOPIC:- SICKLE CELL ANEMIA

3. SICKLE CELL ANEMIA

4. CONTENTS
Definition
History
Hemoglobin
Genetics of SCD
Inheritance of Sickle Cell Disease
Mechanism
Symptoms
Complications
Diagnosis

5. SICKLE CELLANEMIA
Is an inherited form of anemia — a condition in which there aren't
enough healthy red blood cells to carry adequate oxygen
throughout your body.
 Normally, your red blood cells are flexible and round, moving
easily through your blood vessels.
 In sickle cell anemia, the red blood cells become rigid and sticky and
are shaped like sickles or crescent moons.
 These irregularly shaped cells can get stuck in small blood vessels,
which can slow or block blood flow and oxygen to parts of the body.

7. Group member name

8. DEFINITION
Sickle Cell disease: is a genetic disorder that affects
erythrocytes (RBC) causing them to become sickle or
crescent shaped.
 The effects of this condition due to an abnormality
of the hemoglobin molecules found in erythrocytes.

9. HISTORY
In 1904, Walter Clement Noel traveled from Grenada to
the United States to start studying at the Chicago College
of Dental Surgery.
A few months later he was admitted to the Presbyterian
Hospital in Chicago when he developed severe respiratory
distress and a leg ulcer, both of which we now know are
symptoms of sickle cell.
Dr. Earnest E. Irons, the intern who was on duty that day,
performed a routine blood test and a urine analysis for
Noel and was the first to observed these “pear shaped,
elongated” sickled blood cells.

10.  HISTORY
It was not until 1910 that Dr James Herrick, the supervisor of Dr Irons,
published his article describing these “peculiar elongated and sickle
shaped red blood corpuscles in a case of severe anemia.”
This was the first documented and recorded case of Sickle cell in
Western medicine.
Dr Noel returned to Grenada in 1907 and ran his dental practice in St.
Georges, the capital city, until he died at the age of 32 from the acute
chest syndrome.

11. HISTORY
 1917 – Genetic basis for SCD Dr. V. Emmel.
 The third cases of Sickle cell was described in 1915 by Cook and Meyer in a 21-year-old woman.
 Interestingly, blood samples from both the patient and her father, who displayed no symptoms,
showed the sickling deformity of the red cells and three of her siblings had died from severe
anemia.
 These observations made by Dr Emmel suggested a genetic basis for the disease but also led to a
period of confusion with the genetics of the disease.

12. HISTORY
1922 – Dr V.R Mason names the disease Sickle Cell Anemia.
Dr Mason, who observed the fourth reported case of Sickle
cell, was also the first to call the disease “sickle cell anemia”
and to notice the similarities between the cases.
He also noted that all of these patients were black,
inadvertently giving rise to the popular misconception that
sickle cell originated from people of African origin.

13. Supporting content

14. HEMOGLOBIN
The oxygen-carrying pigment and predominant protein in the red blood cells.
Hemoglobin forms an unstable, reversible bond with oxygen.
Oxyhemoglobin: Oxygenated ( bright red).
Deoxyhemoglobin: Reduced ( purple-blue).
Each hemoglobin molecule is made up of four heme groups surrounding a
globin group.
Heme contains iron and gives a red color to the molecule.
Globin consists of two linked pairs of polypeptide chains.

15. HEMOGLOBIN

17. GENETICS OF SCD
The change in cell structure arises from a change in the structure of hemoglobin.
A single change in an amino acid causes hemoglobin to aggregate.

19.  INHERITANCE OF SICKLE CELL DISEASE
If one parent has sickle cell trait (HbAS) and the other
does not carry the sickle hemoglobin at all (HbAA) then
none of the children will have sickle cell anemia.
There is a one in two (50%) chance that any given child
will get one copy of the HbAS gene and therefore have
the sickle cell trait.
It is equally likely that any given child will get two
HbAA genes and be completely unaffected.
 If both parents have sickle cell trait (HbAS) there is a
one in four (25%) chance that any given child could be
born with sickle cell anemia.
There is also a one in four chance that any given child
could be completely unaffected.
There is a one in two (50%) chance that any given child
will get the sickle cell trait.

20. INHERITANCE OF SICKLE CELL DISEASE
If one parent has sickle cell trait (HbAS)
and the other has sickle cell anemia (HbSS)
there is a one in two (50%) chance that any
given child will get sickle cell trait and a one
in two (50%) chance that any given child
will get sickle cell anemia.
No children will be completely unaffected.

21. INHERITANCE OF SICKLE CELL DISEASE
If one parent has sickle cell anemia (HbSS)
and the other is completely unaffected
(HbAA) then all the children will have sickle
cell trait.
None will have sickle cell anemia.
The parent who has sickle cell anemia
(HbSS) can only pass the sickle hemoglobin
gene to each of their children.

24. MECHANISM
When sickle hemoglobin (HbS) gives up its oxygen to the
tissues,HbS sticks together
Forms long rods form inside RBC
RBC become rigid, inflexible, and sickle-shaped
Unable to squeeze through small blood vessels, instead blocks small blood
Less oxygen to tissues of body
RBCs containing HbS have a shorter lifespan
 Normally 20 days
Chronic state of anemia

27. SYMPTOMS
They vary from person to person and change over time, include:
Anemia.
Sickle cells break apart easily and die, leaving you without enough red blood
cells.
Red blood cells usually live for about 120 days before they need to be replaced.
But sickle cells usually die in 10 to 20 days, leaving a shortage of red blood cells
(anemia).
Without enough red blood cells, your body can't get the oxygen it needs to feel
energized, causing fatigue.

29. SYMPTOMS
Episodes of pain:
 Periodic episodes of pain, called crises, are a major symptom of sickle cell
anemia
Pain develops when sickle-shaped red blood cells block blood flow through
tiny blood vessels to your chest, abdomen and joints. Pain can also occur in
your bones.
The pain varies in intensity and can last for a few hours to a few weeks.
Some people have only a few pain episodes. Others have a dozen or more
crises a year. If a crisis is severe enough, you might need to be hospitalized.
Some adolescents and adults with sickle cell anemia also have chronic pain,
which can result from bone and joint damage, ulcers and other causes.

31. SYMPTOMS
 Painful swelling of hands and feet:
The swelling is caused by sickle-shaped red blood cells blocking blood flow to
the hands and feet.
 Frequent infections:
Sickle cells can damage an organ that fights infection (spleen), leaving you
more vulnerable to infections. Doctors commonly give infants and children
with sickle cell anemia vaccinations and antibiotics to prevent potentially life-
threatening infections, such as pneumonia.

33. SYMPTOMS
Delayed growth.
Red blood cells provide your body with the
oxygen and nutrients you need for growth.
 A shortage of healthy red blood cells can slow
growth in infants and children and delay puberty
in teenagers.
Vision problems.
Tiny blood vessels that supply your eyes may
become plugged with sickle cells.
This can damage the retina — the portion of the
eye that processes visual images, leading to
vision problems.

34. Complications of SCD
• Sickle cell anemia can lead to a host of complications, including:
 Stroke.
• A stroke can occur if sickle cells block blood flow to an area of your brain. Signs of stroke include seizures, weakness or
numbness of your arms and legs, sudden speech difficulties, and loss of consciousness. If your baby or child has any of these
signs and symptoms, seek medical treatment immediately. A stroke can be fatal.
 Acute chest syndrome.
• This life-threatening complication causes chest pain, fever and difficulty breathing. Acute chest syndrome can be caused by a
lung infection or by sickle cells blocking blood vessels in your lungs. It might require emergency medical treatment with
antibiotics and other treatments.
 Pulmonary hypertension.
• People with sickle cell anemia can develop high blood pressure in their lungs (pulmonary hypertension). This complication
usually affects adults rather than children. Shortness of breath and fatigue are common symptoms of this condition, which can
be fatal.

37. Complications of SCD
Organ damage.
Sickle cells that block blood flow through blood vessels immediately deprive the affected
organ of blood and oxygen. In sickle cell anemia, blood is also chronically low on oxygen.
Chronic deprivation of oxygen-rich blood can damage nerves and organs in your body,
including your kidneys, liver and spleen. Organ damage can be fatal.
Blindness.
Sickle cells can block tiny blood vessels that supply your eyes. Over time, this can damage
the portion of the eye that processes visual images (retina) and lead to blindness.
Leg ulcers. Sickle cell anemia can cause open sores, called ulcers, on your legs.
Gallstones.
The breakdown of red blood cells produces a substance called bilirubin. A high level of
bilirubin in your body can lead to gallstones.

39. DIAGNOSIS
A blood test can check for hemoglobin S — the defective form of hemoglobin that
underlies sickle cell anemia. In the United States, this blood test is part of routine
newborn screening done at the hospital. But older children and adults can be tested,
too.
In adults, a blood sample is drawn from a vein in the arm. In young children and
babies, the blood sample is usually collected from a finger or heel.
If the screening test is negative, there is no sickle cell gene present.
If the screening test is positive, further tests will be done to determine whether
one or two sickle cell genes are present.
Check for a low red blood cell count (anemia) will be done.

41. GENETIC COUNSELING
• Two tests can be used to help expectant parents find out if their
child is affected.
1. Amniocentesis, done usually at 14-16 weeks of pregnancy,
tests a sample of the amniotic fluid in the womb for genetic
defects (the fluid and the fetus have the same DNA). Under
local anesthesia, a thin needle is inserted through the woman's
abdomen and into the womb. About 20 milliliters of fluid
(roughly 4 teaspoons) is withdrawn and sent to a lab for
evaluation. Test results often take 1-2 weeks.

43. GENETIC COUNSELING
•2. Chorionic Villus sampling,
or CVS, involves the removal and testing of a very small
sample of the placenta during early pregnancy. The
sample, which contains the same DNA as the fetus, is
removed by catheter or a fine needle inserted through the
cervix or by a fine needle inserted through the abdomen.
The tissue is tested for genetic changes identified in an
affected family member. Results are usually available
within 2 weeks.

46. TREATMENT
Treatment is usually aimed at avoiding crises, relieving symptoms and
preventing complications. Babies and children age 2 and younger with
sickle cell anemia should make frequent visits to a doctor.
Children older than 2 and adults with sickle cell anemia should see a
doctor at least once a year, according to the Centers for Disease Control
and Prevention.
Treatments might include medications to reduce pain and prevent
complications, and blood transfusions, as well as a bone marrow
transplant.

48. TREATMENT
 Antibiotics. (Penicillin)
Children with sickle cell anemia may begin
taking the antibiotic penicillin when they're about
2 months old and continue taking it until they're
at least 5 years old.
 Doing so helps prevent infections, such as
pneumonia, which can be lifethreatening to an
infant or child with sickle cell anemia.
 As an adult, if you've had your spleen removed
or had pneumonia, you might need to take
penicillin throughout your life.

49. TREATMENT
Pain-relieving medications.
To relieve pain during a sickle cell crisis.
Hydroxyurea (Droxia, Hydrea).
 When taken daily, hydroxyurea reduces the
frequency of painful crises and might reduce
the need for blood transfusions and
hospitalizations.
Hydroxyurea seems to work by stimulating.

50. TREATMENT
Assessing stroke risk:
 Using a special ultrasound machine
(transcranial), doctors can learn
which children have a higher risk of
stroke.
This painless test, which uses sound
waves to measure blood flow, can be
used on children as young as 2
years.
Regular blood transfusions can
decrease stroke risk.

51. TREATMENT
Vaccinations to prevent
infections:
 Childhood vaccinations are
important for preventing disease
in all children.
Vaccinations, such as the
pneumococcal vaccine and the
annual flu shot, are also
important for adults with sickle
cell anemia.

52. TREATMENT
Blood transfusions
 In a red blood cell transfusion, red blood cells are removed
from a supply of donated blood, then given intravenously to
a person with sickle cell anemia.
 Blood transfusions increase the number of normal red blood
cells in circulation, helping to relieve anemia. In children
with sickle cell anemia at high risk of stroke, regular blood
transfusions can decrease the risk. Transfusions can also be
used to treat other complications of sickle cell anemia, or
they can be given to prevent complications.
Blood transfusions carry some risk, including infection and
excess iron buildup in your body. Because excess iron can
damage your heart, liver and other organs, people who
undergo regular transfusions might need treatment to reduce
iron levels.

53. TREATMENT
 Nitric oxide:
 People with sickle cell anemia have low levels of nitric oxide in their
blood.
Nitric oxide is a gas that helps keep blood vessels open and reduces the
stickiness of red blood cells.
Treatment with inhaled nitric oxide might prevent sickle cells from
clumping together. Studies on nitric oxide have shown little benefit so
far.

55. TREATMENT
•Bone Marrow Transplant:
Bone marrow transplant, also known as stem cell transplant, offers the only potential cure for
sickle cell anemia.
 It's usually reserved for people younger than age 16 because the risks increase for people older
than 16.
Finding a donor is difficult, and the procedure has serious risks associated with it, including
death.
A bone marrow transplant involves replacing bone marrow affected by sickle cell anemia with
healthy bone marrow from a donor.
The procedure usually uses a matched donor, such as a sibling, who doesn't have sickle cell
anemia.
For many, donors aren't available. But stem cells from umbilical cord blood might be an option.

56. TREATMENT
•Bone marrow transplant
 Because of the risks associated with a bone marrow transplant, the procedure is
recommended only for people, usually children, who have significant symptoms
and problems from sickle cell anemia.
 If a donor is found, the person with sickle cell anemia receives radiation or
chemotherapy to destroy or reduce his or her bone marrow stem cells. Healthy
stem cells from the donor are injected intravenously into the bloodstream of the
person with sickle cell anemia, where they migrate to the bone marrow and begin
generating new blood cells.
The procedure requires a lengthy hospital stay. After the transplant, you'll receive
drugs to help prevent rejection of the donated stem cells.

58. EXPERIMENTAL TREATMENTS
• Scientists are studying new treatments for sickle cell
anemia, including:
Gene therapy.
Researchers are exploring whether inserting a normal
gene into the bone marrow of people with sickle cell
anemia will result in normal hemoglobin.
 Scientists are also exploring the possibility of
turning off the defective gene while reactivating
another gene responsible for the production of fetal
hemoglobin — a type of hemoglobin found in
newborns that prevents sickle cells from forming.
Potential treatments using gene therapy are a long
way off, however.

61. REFERENCES:
•https://www.youtube.com/watch?v=iTm7jHIZAic&feature
=youtu.be
•https://www.slideshare.net/MohamedElasalyPTCKTP/si
ckle-cell-anemia-75934817
•https://www.healthline.com/health/sickle-cell-
anemia#complications
https://www.slideshare.net/hytham_nafady/sickle-cell-
anemia-23178648