Post by fascinating on Mar 4, 2017 9:34:01 GMT 1
Well, for one person anyway.
As far as I know, this is the first real example of gene editing to remedy an abnormality in the functioning of the body's biochemistry.
Members will know that genes within DNA are made up of bases (parts of molecules) adenine, thymine, cytosine and guanine, represented as A, T, C and G. Proteins are made when ribosomes attach to the RNA (which is a transcription of a functional strand of DNA) and "read" the code in groups of 3. Each group of 3 is called a codon and codes for a specific amino acid.
In position 7 of a standard haemoglobin molecule, the amino acid glutamic acid should be there, but in the disease it is valine. The reason this happens is down to one single base of, in DNA, adenine being replaced by thymine, so that instead of being CAG the codon, in DNA, reads CTG. In the RNA copy the codon becomes CUG (U being uracil) instead of CAG, and that causes valine to be put in place.
This type of haemoglobin does not conform properly and causes the red blood cell to twist and fold to the sickle-cell shape, but more importantly it is inefficient at carrying oxygen (though the actual reason for the lack of oxygen in the blood is apparently that the body keeps destroying these dysfunctional cells, and is not able to produce replacement cells fast enough).
To remedy the problem, my understanding is that they had to take tissue from the bone marrow and edit it in vitro using a retrovirus, then inject the corrected stem cells back into the body.
As far as I know, this is the first real example of gene editing to remedy an abnormality in the functioning of the body's biochemistry.
Members will know that genes within DNA are made up of bases (parts of molecules) adenine, thymine, cytosine and guanine, represented as A, T, C and G. Proteins are made when ribosomes attach to the RNA (which is a transcription of a functional strand of DNA) and "read" the code in groups of 3. Each group of 3 is called a codon and codes for a specific amino acid.
In position 7 of a standard haemoglobin molecule, the amino acid glutamic acid should be there, but in the disease it is valine. The reason this happens is down to one single base of, in DNA, adenine being replaced by thymine, so that instead of being CAG the codon, in DNA, reads CTG. In the RNA copy the codon becomes CUG (U being uracil) instead of CAG, and that causes valine to be put in place.
This type of haemoglobin does not conform properly and causes the red blood cell to twist and fold to the sickle-cell shape, but more importantly it is inefficient at carrying oxygen (though the actual reason for the lack of oxygen in the blood is apparently that the body keeps destroying these dysfunctional cells, and is not able to produce replacement cells fast enough).
To remedy the problem, my understanding is that they had to take tissue from the bone marrow and edit it in vitro using a retrovirus, then inject the corrected stem cells back into the body.