Modified RNA has a direct effect on DNA
https://phys.org/news/2020-01-rna-effect-dna.html
In areas of DNA where RNA binds to one of the DNA threads in such a way that the complementary DNA thread becomes the sole thread (R-loop structures), the DNA stability will change if RNA is chemically modified by m6A.
“Several research groups are now working together to study what effect this can have on the DNA molecule. We already know that R-loop areas are associated with sequences of DNA containing active genes and that this can lead to chromosomal breakage and the loss of genetic information,” explains Klungland.
U.S. National Library of Medicine
What is epigenetics?
https://medlineplus.gov/genetics/understanding/howgeneswork/epigenome/
DNA modifications that do not change the DNA sequence can affect gene activity.
Epigenetic changes can help determine whether genes are turned on or off and can influence the production of proteins in certain cells, ensuring that only necessary (desired) proteins are produced.
Because errors in the epigenetic process, such as modifying the wrong gene or failing to add a compound to a gene, can lead to abnormal gene activity or inactivity, they can cause genetic disorders. Conditions including cancers, metabolic disorders, and degenerative disorders have all been found to be related to epigenetic errors.