Sickle Cell Anemia

1) Single nucleotide substitution (“point mutation”) in the genefor the beta chain of hemoglobin.

3) Beta chain synthesized from the sickle-cell allele does not“fold” correctly and hempglobin molecules “clump” togetherforming a red blood cell that resembles a sickle.

2) Different amino acid gets placed in the peptide chain..

4) Sickled cells die early (10-20 days vs. 120 days) producing anemia.

5) Sickled cells clog the fine capillaries, leading to lack of oxygen intarget organs.

http://bio.winona.msus.edu/berg/308s04/Lec-note/19-new.htm

Rapid breakdownof sickled cells

Hemoglobin molecules “clump”

Sickle-shape red blood cells

Skeletalproblems

Impededcirculation

Organdamage

PainInfection

risk

Overactivebone marrow

FatigueImpaired

development

Anemia

http://www.ncbi.nlm.nih.gov/books/bv.fcgi?call=bv.View..ShowSection&rid=gnd.section.98

http://peptide.ncsa.uiuc.edu/tutorials_current/Sickle_Cell_Anemia/SC2001/intro.html

http://www.blackwellpublishing.com/ridley/images/sickle_cell_anaemia.jpg

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

Why is SCA so common in some areas?

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

Different origins (independent mutations) of the SCD allele