Sickle Cell Anemia

A trait due to a change in ONE nucleotide in the DNA sequence that leads to a change in ONE amino acid that changes how the hemoglobin protein folds. This change in the structure of the hemoglobin protein leads to a change in the shape of the red blood cell to a sickle shape.

Sickle Cell Anemia and Malaria Resistance

Difference in Sickle Cell Hemoglobin Coding Sequence (Mutation and its Ramifications)

Medical and Clinical Links

Sickle Red Blood Cell
Normal Red Blood Cell

http://www.blc.arizona.edu/courses/181gh/rick/human_genetics/diseases.html

http://webpub.alleg.edu/dept/bio/bio221/

http://be-research.ucsd.edu/research/research_groups/compbio/bioph254/public_html/Class-slides/Lect14/figure53.html

DNA Sequence

  • normal
  • sickle

 

  • ATG GTG CAC CTG ACT CCT GAG GAG AAG TCT GCC GTT ACT
  • ATG GTG CAC CTG ACT CCT GTG GAG AAG TCT GCC GTT ACT
http://www.district86.k12.il.us/central/departments/science/Project/chromosome11.mazurek/

Protein Sequence

  • normal
  • sickle

 

  • MVHLTPEEKSAVT (E is the single letter abbreviation for glutamic acid)
  • MVHLTPVEKSAVT (V is the single letter abbreviation for valine)

Glutamic acid is a hydrophilic amino acid. Valine is a hydrophobic amino acid.

http://www.district86.k12.il.us/central/departments/science/Project/chromosome11.mazurek/

The change from GAG to GTG changes the ability to be cut by the restriction enzyme MstII. Here is a schematic of what the normal (A) vs sickle (S) restriction patterns look like.

and here, relating the gel electrophoresis pattern to the inheritance pattern or pedigree