La risposta breve
Gene editing means going into a cell and changing the DNA that is already there — at one particular spot you have chosen. That is different from older genetic engineering, which mostly added new DNA somewhere and hoped it landed usefully. The difference between adding and changing is the single most useful thing to understand about this whole field.
Gene editing introduces targeted, permanent changes at specified genomic loci in living cells, in contrast to gene addition, which delivers a transgene without altering the endogenous sequence. Editing platforms include zinc finger nucleases, TALENs and CRISPR-based systems; the shared requirement is sequence-specific targeting. Somatic editing affects only the treated individual; germline editing would be heritable and is prohibited or unapproved for clinical use in most jurisdictions.
Editing versus gene therapy, plainly
| Gene addition (classic gene therapy) | Gene editing | |
|---|---|---|
| What it does | Adds a working copy of a gene | Changes the DNA already present |
| The faulty gene | Left in place | Altered, disabled or corrected |
| Best for | A missing protein | A harmful protein, or a change in how much is made |
| Durability | Can fade as cells divide, with non-integrating vectors | Inherited by every daughter cell |
| Maturity | Several approved products | One approved product |
Both are usually given once and both are permanent for the cells they reach. They are routinely conflated, including in serious coverage.
What editing cannot do
Common questions
Is gene editing the same as GMO?
Related but not identical. A classic genetically modified organism carries DNA inserted from another species. Gene editing usually changes the organism's own sequence and often leaves nothing foreign behind — which is why several countries regulate edited crops differently from transgenic ones.
Does gene editing change your children?
Not as practised in medicine. Approved and clinical uses are somatic and are not inherited. Heritable germline editing is prohibited or unapproved for clinical use in most countries.
Sources
- National Human Genome Research Institute
Talking Glossary of Genomic Terms ↗