A Brief Overview of Sickle Cell A Brief Overview of Sickle Cell AnemiaAnemia

By: Aaron BushBy: Aaron Bush

Case #1Case #1

Case 1: Congratulations! It's a girlCase 1: Congratulations! It's a girlMy husband's father and his sister have My husband's father and his sister have Sickle Sickle

CellCell disease. My aunt also has the same disease. My aunt also has the same disorder. What is the risk of this child having disorder. What is the risk of this child having the sickle cell disease? My husband's the sickle cell disease? My husband's company is sending him to East Africa for company is sending him to East Africa for two years. Our newborn baby and I are going two years. Our newborn baby and I are going with him. We just heard on the news that the with him. We just heard on the news that the region we are moving to has an outbreak of region we are moving to has an outbreak of MalariaMalaria. How likely are we to get malaria?. How likely are we to get malaria?

DescriptionDescription

Sickle Cell anemia is an Sickle Cell anemia is an inherited red blood cell inherited red blood cell disorder. Normal red disorder. Normal red blood cells are round like blood cells are round like bagels. Sickle red blood bagels. Sickle red blood cells are hard, and shaped cells are hard, and shaped like sickles, formerly like sickles, formerly used to cut grain. When used to cut grain. When these hard and pointed these hard and pointed red cells go through small red cells go through small arteries, they clog the arteries, they clog the blood flow and can break blood flow and can break apart causing great pain.apart causing great pain.

CauseCause

Sickle Cell is caused by Sickle Cell is caused by a point mutation of the a point mutation of the DNA that codes for DNA that codes for the formation of the formation of hemoglobin (the hemoglobin (the substance that carries substance that carries oxygen in red blood oxygen in red blood cells)cells)MutationMutation

GAG ==> GUG orGAG ==> GUG orGAA ==> GUAGAA ==> GUA

This mutation from valine into glutamic acid is found on the 6th position of Chromosome 11 where the hemoglobin is coded.

EffectsEffects

Symptoms of sickle cell disease Symptoms of sickle cell disease include:include:FeverFeverChest painChest painIncreasing tirednessIncreasing tirednessShortness of BreathShortness of BreathAbdominal swellingAbdominal swellingUnusual headacheUnusual headacheSudden weakness or loss of Sudden weakness or loss of feelingfeelingPain that will not go away with Pain that will not go away with self-treatmentself-treatmentSudden vision change Sudden vision change Stroke (occurs in 6- 8% of people Stroke (occurs in 6- 8% of people with sickle cell)with sickle cell)

Population AffectedPopulation Affected

Sickle Cell is most prevalent Sickle Cell is most prevalent in Africa, where 1/350 in Africa, where 1/350 have the disease.have the disease.

It it also found in lesser It it also found in lesser amounts in the amounts in the

Middle EastMiddle EastMediteranean Sea areaMediteranean Sea areaGreeceGreeceItalyItalyLatin AmericasLatin AmericasIndiaIndia

InheritanceInheritance

Sickle cell is an autosomal Sickle cell is an autosomal recessive trait, meaning recessive trait, meaning that to have the disorder that to have the disorder you must be homozygous you must be homozygous recessive, or ss. A Ss, or recessive, or ss. A Ss, or SS individual would not SS individual would not have the disorder.have the disorder.

When dealing with sickle When dealing with sickle cell the letters S and A are cell the letters S and A are commonly used to commonly used to distinguish between distinguish between normal hemoglobin (A), normal hemoglobin (A), and sickle cell hemoblobin and sickle cell hemoblobin (S). AS shows a carrier.(S). AS shows a carrier.

Care, Cure & PreventionCare, Cure & Prevention

There is no cure for sickle cell.There is no cure for sickle cell.People with this disorder should People with this disorder should

have: have: Adequate oxygenAdequate oxygenPlenty of waterPlenty of waterTake folic acid Take folic acid supplementssupplementsTake penicillin and be Take penicillin and be immunized for many immunized for many diseasesdiseases

Bone marrow transplants are Bone marrow transplants are also recommended, help the also recommended, help the body make normal red blood body make normal red blood cells.cells.

ProbabilityProbability

The probability of this child The probability of this child getting sickle cell depends getting sickle cell depends on the genotype of the on the genotype of the mother which cannot be mother which cannot be determined from the determined from the information given. It can information given. It can only be determined that only be determined that the mother is either a the mother is either a carrier, or normal.carrier, or normal.

If the mother is a carrier the the child will have a 25% chance of inheriting the disorder. They have a 50% chance of being a carrier, and a 25% chance of being normal.

If the mother is not a carrier 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.

SS Ss

Ss ss

S s

S

s

SS Ss

SS Ss

S s

S

S

Family PedigreeFamily Pedigree

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Male Female

Sickle CellCarrierNormal

Key

Malaria & Sickle CellMalaria & Sickle Cell

People who are homozygous People who are homozygous recessive for sickle cell (aa) recessive for sickle cell (aa) are resistant to malaria are resistant to malaria because their misshapen, because their misshapen, deflated red cells are poor deflated red cells are poor hosts. However, many of hosts. However, many of these sickle cell individuals these sickle cell individuals die in childhood from die in childhood from sickle-cell anemia and sickle-cell anemia and related health problems.related health problems.

People who are heterozygous People who are heterozygous (Aa) for sickle-cell trait also (Aa) for sickle-cell trait also have moderately good have moderately good resistance to malaria because resistance to malaria because some of their red cells are some of their red cells are misshapen and deflated, these misshapen and deflated, these individuals rarely develop the individuals rarely develop the severe life threatening anemia severe life threatening anemia and related problems typical and related problems typical of homozygous recessive (aa) of homozygous recessive (aa) individuals. Those who are individuals. Those who are homozygous dominant (AA) homozygous dominant (AA) produce normal red blood produce normal red blood cells, which makes them cells, which makes them excellent hosts for malaria. excellent hosts for malaria.

ResourcesResources

http://anthro.palomar.edu/synthetic/http://anthro.palomar.edu/synthetic/synth_7.htmsynth_7.htm

http://www.scinfo.org/sicklept.htmhttp://www.scinfo.org/sicklept.htm

http://courses.nus.edu.sg/course/patleesh/ha/http://courses.nus.edu.sg/course/patleesh/ha/sickle.htmsickle.htm

http://www.vh.org/pediatric/patient/http://www.vh.org/pediatric/patient/pediatrics/faq/sicklecell.htmlupediatrics/faq/sicklecell.htmlu