Hello Meilani Salsabila Daulay

The information is available on google. Nevertheless, I came across these links below which may be helpful.

https://bscb.org/learning-resources/softcell-e-learning/section-4-what-causes-mutations/

https://bscb.org/learning-resources/softcell-e-learning/section-4-what-causes-mutations-more-details/

Best.

Again, this site is for research questions. You need to learn these basics for yourself.

Also, not all mutations are in genes. I'll give you that one for free.

A more mechanistic answer might be as follows:

- replication error

- DNA damage + replication

- DNA damage + inaccurate repair

but I may be forgetting other cases

Mutations may be germline or somatic. Germline mutations, such as BRCA gene mutations, are generally deteriorative for the genomic machinery and increase cancer risk via disturbing certain DNA repairing processes. Somatic mutations may be originated from environmental influences, such as endocrine disruptor xenoestrogens, smoking and other toxins. These environmental effects initially inhibit certain important genetic pathways and later they may induce compensatory mutations repairing the genomic failures and preserving the health. In tumors, activating mutations are frequently found. These mutations are not oncogenic but rather they try to improve genome stabilization, metabolic activation and immune reactions serving apoptotic death. Tumors have some genomic plasticity helping DNA repair and survival of patients. Tumors need medical help for the improvement of their genomic defects rather than further “therapeutic” DNA damage.

Oncol Rev., 19 April 2023 https://doi.org/10.3389/or.2023.10708