Sickle Cell Disease

1. Sickle Cell Disease

2. Hemoglobin • Protein made of many amino acids • The sequence of amino acids is genetic coded by DNA • Function to carry oxygen and other compounds

3. Genetic Process • DNA contains compounds called bases– adenine, thymine, guanine and cytosine– in a genetic coded sequence • mRNA– matches up to those bases and reads the message– where an adenine/thymine, guanine/uracil etc • Moves to cytoplasm of cell and waits for t-RNA carrying the amino acid to find the right sequence and drop off its amino acid

4. www.vcbio.science.ru.nl/ images/cellcycle/mcel...

5. http://fig.cox.miami.edu/~cmallery/150/chemistry/hemoglobin.jpghttp://fig.cox.miami.edu/~cmallery/150/chemistry/hemoglobin.jpg

6. Normal Pathology • Inherit 2 copies of the gene called Alleles • When born have Hemoglobin F • By 3 months replaced by Hemoglobin A

7. Sickle Cell • Caused by a SNP– single nucleotide polymorphism • DNA has Adenine (A base) replaced by Thymine (T base) • So Code is GTG instead of GAG • Valine get put in place of Glutamic acid in 6th amino acid of both beta chains

8. Sickle Cell continued • Under certain conditions such as low O2 , the hemoglobin molecules stick together or polymerize • Stretches the Red Blood Cells to look like a “sickle” • Affects about 8-11% of African Americans

9. http://www.healthsystem.virginia.edu/internet/hematology/HessImages/Sickle-Cell-Disease-40x-website.jpghttp://www.healthsystem.virginia.edu/internet/hematology/HessImages/Sickle-Cell-Disease-40x-website.jpg

10. Problems • Cells can’t move thru microvessels • Blood get thick or viscous • Spleen removes the defective cells • Stroke • Infections • Difficulty breathing • Pain • Organ failure or damage

11. Treatment • Antibiotics started very early in children • Transfusions • Drugs to Aid in production of Hemoglobin F • Hydroxyurea • Butyrate • IV dose and oral 30-40 tablets per day • Pulse therapy • Bone Marrow Transplantation