DNA is “altered” all the time. There are transposon and retrotransposon additions. There is translocation errors. There are SNP mutations. Fortunately there are editing functions and mutation suppression going on. The problem is even the correction systems going on will mutate.
Please buy yourself, or go to a big public or university library, where you can read a college level text on genetics.
You will not get good information by listening to most of internet snippets of info. It takes lots of work.
And yet a teenager with Purple hair that works at CVS can inject you with this Experiment.