From BBC News.
This is amazing news, and offers great hope. However, I do wonder about the permanence of the treatment.
“The concept of gene therapy is that it corrects gene defects. Ideally we should only have to do that once, because once the DNA is corrected and inserted into the correct cell, that cell should be able to continue its function as normal,” [Prof Robert MacLaren of Oxford University] told BBC News.
I admit to a poor understanding of biology, so perhaps other readers can help me. Are not the cells of the cell mortal? Don’t they die off, to be replaced by new cells, over the course of an individual’s life? I think that is true of our bones, but perhaps eyes are different.
Cells still reproduce before they die. As the corrected cells reproduce, their offspring will retain the correction, allowing it to continue and spread.
Note that I am not a biologist, but yes the new cells would die off. Each cell type in the body has a different life time (from days to a lifetime)
Assuming that the faulty gene (or genes) were corrected the new genes would be passed on during cell replication. The question would be if the treatment would replace/repair the faulty genes in the majority of the cells or only a portion. Cells also have a limited number of times that they can replicate based on the length of the telomeres (something like 40 or 50 times?). If the therapy were to leave some ratio of damaged genes and shortened the telomeres in cells that were “fixed” I would think that you would have the genetic defect become more pronounced overtime as the “fixed” cells began to stop replicating and replaced by the cells with faulty genes. On the other hands it they introduce higher levels of telomerase to help replication (protects telomers from shortening during replication) it could introduce cancerous growths in the “fixed” cells. I guess much of it would revolve around how the faulty genes are corrected and the replication rate of the cells in question?
It apparently does work. Gene editing/therapy is not fully explained regarding the length of time it would remain functional. Then there would be the case of unedited cells still existing at the site. Ask your eye doctor.
This is a good thing. It gives people who have lost their sight hope.