How exactly do you edit a gene? Like, it is very, very small thing. How do you even measure it, let alone replace it?
Keywords to search for "CRISPR Cas9"
First UK child to receive gene therapy for fatal genetic disorder is now healthy
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Re: First UK child to receive gene therapy for fatal genetic disorder is now healthy
#112Thats a new stealth weapon for the global population to watch out for now, knowing how things work in this country.
Re: First UK child to receive gene therapy for fatal genetic disorder is now healthy
#113Thats a new stealth weapon for the global population to watch out for now, knowing how things work in this country.
Please elaborate.
Re: First UK child to receive gene therapy for fatal genetic disorder is now healthy
#114Re: First UK child to receive gene therapy for fatal genetic disorder is now healthy
#115Earlier quoted context omitted.
Yes, it's a virus, specifically a lentivirus, which inserts its own genome into the cells DNA, including the therapeutic gene. Looks like they first extract bone marrow from a patient, apply the virus which adds the gene, then they put the "fixed" bone marrow cells back into the patient (probably after killing most existing bone marrow through some really unpleasant procedures). The re-inserted, treated cells then ex…
So is the idea here that the 'fixed' cells populate the body and form the basis of all future generations of cells that are produced in the bone marrow?
Yep!
Re: First UK child to receive gene therapy for fatal genetic disorder is now healthy
#116I wonder if a similar approach can be used for Von Hippel Landau. “ Mutations in the VHL gene cause von Hippel-Lindau syndrome. The VHL gene is a tumor suppressor gene, which means it keeps cells from growing and dividing too rapidly or in an uncontrolled way. Mutations in this gene prevent production of the VHL protein or lead to the production of an abnormal version of the protein. An altered or missing VHL protein…
I am not an expert but you would need much more transformation. Missing enzyme in white blood cell is simple: any unreached cells are not a problem. Defective protein in all cells is hard.
Re: First UK child to receive gene therapy for fatal genetic disorder is now healthy
#117Earlier quoted context omitted.
The world doesn't have unlimited resources. You have to make a call somewhere.
Governments and non-profits already funded the development of gene therapy. Letting private companies charge money for it and then blocking people who need it from getting it is a policy decision.
This argument ignores the finite resource fact.
No policy decision can change that.
Re: First UK child to receive gene therapy for fatal genetic disorder is now healthy
#118How exactly do you edit a gene? Like, it is very, very small thing. How do you even measure it, let alone replace it?
Biochemistry is wild!
Measuring is an absolutely fascinating procedure. The predominant method is called sequencing by synthesis. Illumina is the company that basically rules the market for this technology, they have some decent explanatory videos if you’re interested.
The first steps are to isolate DNA, then break it into small bits, replicate those small pieces thousands of times, and then anchor these to a glass slide. Then flow a solution over the slide with the individual DNA bases (ATCG) that have been modified to fluoresce when illuminated with a certain wavelength of light. These fluorescently labeled nucleotides get assembled one by one into strands that match the small fragments from the DNA sample. Each time the fluorescent DNA bases are added a laser is shined on the glass slide and a very sensitive microscope camera reads how many strands shone at the frequency that corresponds to A T C and G. This tells you which base just got added to which strand. Repeat a couple hundred times and you have a huge number of sequences of ATCG’s corresponding to each short strand of DNA in the sample.
The problem now is assembling these short sequences into a full genome. Basically, the puzzle is finding the arrangement of short sequences that maximizes the overlap between them and their agreement with a reference genome. It’s a pretty interesting problem that (I believe) is classically solved with dynamic programming, although I don’t know the most recent methods.
I really don’t think it’s well enough appreciated how integral computation is to DNA sequencing. Signal processing in the camera, assembling the genome fragments, determining whether a mutation exists, and all the subsequent analysis to give biological meaning to a sequence.
Edit: editing is a whole other, extremely complicated procedure. In fact, direct editing isn’t really possible now. Instead we can basically just delete and insert.
Re: First UK child to receive gene therapy for fatal genetic disorder is now healthy
#119How exactly do you edit a gene? Like, it is very, very small thing. How do you even measure it, let alone replace it?
With DNA sequencing?
Re: First UK child to receive gene therapy for fatal genetic disorder is now healthy
#120How exactly do you edit a gene? Like, it is very, very small thing. How do you even measure it, let alone replace it?
Biochemistry is wild! Measuring is an absolutely fascinating procedure. The predominant method is called sequencing by synthesis. Illumina is the company that basically rules the market for this technology, they have some decent explanatory videos if you’re interested. The first steps are to isolate DNA, then break it into small bits, replicate those small pieces thousands of times, and then anchor these to a glass s…
Your answer is much better