[colechristensen]

Eh, while that's true for many things, there are plenty of genetic diseases for which it is not ("diseases" or whatever you might call the human lack of vitamin C synthesis)

In this case the gene encoding L-gulonolactone_oxidase is broken, and that's the last step in the process. That gene catalyzes something into a substance which decays into vitamin C.

[roywiggins]

First you need a gene therapy delivery system that doesn't produce any off-target mutations at all, ever.

[colechristensen]

Extract tissue from patient, build a cell line, CRISPR in vitro, build a cell line, sequence to verify. Use verified cell line to build pseudo-organs or to inject cells or stem cells.

ex vivo gene therapy.

[roywiggins]

Cells don't survive sequencing, any that you do implant have not been sequenced. At best you can get some confidence that the error rate is small.

[colechristensen]

This is why I said build a cell _line_, i.e. cells that all come from a single parent cell. Clones. Make monoclonal stem cell lines, use CRISPR on them, make a NEW monoclonal cell line post-CRISPR and pull some cells to validate success or failure.