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 apart causing great pain.

Cause Sickle Cell is caused by a point mutation of the DNA that codes for the formation of hemoglobin (the substance that carries oxygen in red blood cells) Mutation GAG ==> GUG or GAA ==> GUA This mutation from valine into glutamic acid is found on the 6th position of Chromosome 11 where the hemoglobin is coded.

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 Latin Americas India

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, help the body make normal red blood cells.

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

Family Pedigree

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

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