Download Sickle Cell Anemia

A Brief Overview of Sickle Cell
Anemia
By: Aaron Bush
Case #1
Case 1: Congratulations! It's a girl
My husband's father and his sister have Sickle
Cell disease. My aunt also has the same
disorder. What is the risk of this child having
the sickle cell disease? My husband's
company is sending him to East Africa for
two years. Our newborn baby and I are going
with him. We just heard on the news that the
region we are moving to has an outbreak of
Malaria. How likely are we to get malaria?
Description
Sickle Cell anemia is an
inherited red blood cell
disorder. Normal red
blood cells are round
like bagels. Sickle red
blood cells are hard,
and shaped like sickles,
formerly used to cut
grain. When these hard
and pointed red cells go
through small arteries,
they clog the blood
flow and can break
Cause
Sickle Cell is caused by This mutation from valine
into glutamic acid is
a point mutation of the
found on the 6th
DNA that codes for
position of
the formation of
Chromosome 11 where
hemoglobin (the
the hemoglobin is
substance that carries
coded.
oxygen in red blood
cells)
Mutation
GAG ==> GUG or
GAA ==> GUA
Effects
Symptoms of sickle cell disease
include:
Fever
Chest pain
Increasing tiredness
Shortness of Breath
Abdominal swelling
Unusual headache
Sudden weakness or loss of
feeling
Pain that will not go away with
self-treatment
Sudden vision change
Stroke (occurs in 6- 8% of people
with sickle cell)
Population Affected
Sickle Cell is most
prevalent in Africa,
where 1/350 have the
disease.
It it also found in lesser
amounts in the
Middle East
Mediteranean Sea
area
Greece
Italy
Inheritance
Sickle cell is an autosomal
recessive trait, meaning
that to have the disorder
you must be homozygous
recessive, or ss. A Ss, or
SS individual would not
have the disorder.
When dealing with sickle
cell the letters S and A are
commonly used to
distinguish between
normal hemoglobin (A),
and sickle cell hemoblobin
(S). AS shows a carrier.
Care, Cure & Prevention
There is no cure for sickle
cell.
People with this disorder
should have:
Adequate oxygen
Plenty of water
Take folic acid
supplements
Take penicillin and be
immunized for many
diseases
Bone marrow transplants
are also recommended,
Probability
The probability of this child
getting sickle cell depends If the mother is a carrier the
the child will have a 25%
on the genotype of the
chance of inheriting the
mother which cannot be
disorder. They have a 50%
determined from the
chance of being a carrier,
information given. It can
and a 25% chance of being
only be determined that
normal.
the mother is either a
carrier, or normal.
If the mother is not a carrier
S
s
S
s
S
SS Ss
S
SS Ss
s
Ss
S
SS Ss
ss
the chance that the child
will inherit the disorder is
0%. It will have a 50%
chance of being a carrier,
and a 50% chance of being
normal.
Family Pedigree
Key
Male Female
?
Sickle Cell
Carrier
Normal
?
?
?
?
?
Malaria & Sickle Cell
People who are homozygous
People who are
recessive for sickle cell
heterozygous (Aa) for
(aa) are resistant to
sickle-cell trait also have
malaria because their
moderately good
misshapen, deflated red
resistance to malaria
cells are poor hosts.
because some of their red
However, many of these
cells are misshapen and
sickle cell individuals die
deflated, these individuals
in childhood from sicklerarely develop the severe
cell anemia and related
life threatening anemia
health problems.
and related problems
typical of homozygous
recessive (aa) individuals.
Those who are
Resources
http://anthro.palomar.edu/synthetic/synth_7.h
tm
http://www.scinfo.org/sicklept.htm
http://courses.nus.edu.sg/course/patleesh/ha/s
ickle.htm
http://www.vh.org/pediatric/patient/pediatrics
/faq/sicklecell.htmlu