Consider the Following Patient

Two year-old Zola and her parents just recently

moved to the United States from Southern Africa.

Zola has been having many painful health

problems and developmental delays. Zola has

had troubles healing from cuts and wounds and

she also suffers from severe swelling in her

fingers and toes. Those symptoms are

accompanied by fever, paleness, dehydration,

fatigue, and pneumonia like symptoms.

What would your initial diagnosis be for

Zola?

Anemia

What tests would you preform to strengthen your

diagnosis for Zola?

Blood Testing Hemoglobin electrophoresis – used to separate abnormal

hemoglobin's by their charged migrations down an electrical field

Hemoglobin S results in sickle-cell anemia from an amino acid substitution of Val instead of Glu. Valine has a R group with no electrical charge whereas glutamate has a negative charge. Therefore hemoglobin S has two fewer negative charges than the normal hemoglobin A.

Hemoglobin fractionation by HPLC

Isoelectric focusing

Genetic Testing

SICKLE-CELL ANEMIA

By: Madison Hanson

Hemoglobin

Protein in your red blood cell that carries oxygen to your cells

Oxygen attaches to the iron containing part of hemoglobin

Blood contains iron discovered in 1747

Chemical structure of hemoglobin discovered in 1960s

Depending on health, hemoglobin is able to carry up to four oxygen molecules

Hemoglobin Molecular

Structure

• The amino acids form alpha

helices

• The alpha subunits are red (2)

• The beta subunits are blue (2)

• The iron containing heme

groups are green (4)

• Hydrogen bonds stabilize

hemoglobin

• Salt bridges and the

hydrophobic effect bind the

polypeptides

Case Study

Sickle-cell anemia is diagnosed by the type of

hemoglobin found in the blood

Normal hemoglobin A is disk shaped and flows

throughout the blood vessels with ease

Sickle-cell hemoglobin S is C shaped and will

build up and cause obstructions in the blood

vessels

Treatment

Medications Antibiotics to lower risk of infection

Pain-relieving medication

Hydroxyurea – decreases serious complications, reduce need for blood transfusions, and prevents sickling of blood cells

Ribonucleic Reductase Inhibitor - interferes with the growth of the abnormal hemoglobin and produces more fetal hemoglobin. This medication is also used for cancer treatment where it interferes with the growth of the cancer cells by inhibiting the formation of deoxyribonucleotides, which are the building blocks for DNA. Essentially, this medication does not allow the S phase of the cell cycle to replicate the DNA, therefore reducing the replication of the cancer cells.

Blood Transfusions

Bone Marrow Transplant (rare)

References

Chhabra, Namrata. "Hydroxyurea in the Treatment of Leukemia." Biochemistry for Medics - Clinical Cases. N.p., 13 Mar. 2016. Web. 14 Dec. 2016.

"Facts About Sickle Cell Disease." Centers for Disease Control and Prevention. Centers for Disease Control and Prevention, 17 Nov. 2016. Web. 11 Dec. 2016.

"Haemoglobin." The Oxford Companion to the Body. Encyclopedia.com, n.d. Web. 11 Dec. 2016.

Indian J Hematol Blood Transfus. 2014 Jun; 30(2): 91–96. Published online 2013 May 24. doi: 10.1007/s12288-013-0261-4

Sickle Cell Anemia. N.p., 11 June 2014. Web.

"Sickle Cell Tests." Sickle Cell Tests: The Test. N.p., n.d. Web. 11 Dec. 2016.