What happens when a change in the DNA of an egg or sperm is not repair will depend on the location of the mutation. This means that whether the changed DNA region is a gene, a regulating sequence or "junk" DNA, the cell can survive or not. In case it survives, the replaced nucleotide may not altere the protein it codifies, resulting in a silent mutation, or it can cause altereations in the functioning even though not being lethal.
