Sickle Cell Trait

While at Cambridge in 1956 Vernon Ingram (late of MIT)
discovered that it was a single amino acid substitution
in the beta globin protein that was responsible for the
molecular abnormality leading to Sickle Cell Anemia.

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sickle trait
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Molecular basis of the sickle beta-globin mutation

    Treatments:



   Treatments for Sickle Cell Disease:

1.    Dec 1998: Keone Penn was the first person to be cured of sickle cell disease
               through umbilical cord blood stem cell treatment.

2.    Bone marrow transplant are a prescribed treatment in use today.

3.    Oral medications that prevents sickle shape and binding together.

4.    Blood transfusions in severe anemia cases and increase number of RBCs.

5.    2023 Casgevy is a gene editing drug cuts in a particular gene that can
       reactivate the production of fetal hemoglobin, which dilutes the faulty
       red blood cells caused by sickle cell disease.

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                               or    DdeI-cuts

Sickle Cell disease occurs when the DNA sequence for glutamic acid is converted to valine.
This results from a change in the nucleotide T to A.
This change eliminates a site recognized by the restriction enzyme DdeI, that comes
from the bacteria Desulfovibrio desulfuricans

Restriction enzyme: DdeI (cuts DNA at recognition sequence: 5'-C^TNAG-3')

Pattern result: normal cell = 3 fragments (1 large, a 201bp piece, and a 175bp piece)
                         sickle cell = 2 fragments (1 large piece and a 376bp piece)

   fig 20.9* Thus the number of RFLP piece can indicate presence of defective alleles.

DdeI is a restriction enzyme isolated from Desulfovibrio desulfuricans, a Gram-negative sulfate
reducing soil bacteria) that can digest 1ug DNA in 1 hr @ 37C at cut site 5'C|TNAG3'
3'GANT|C5'

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