Insertion/deletion - one or more nucleotide pairs are put in/taken out of a sequence -> causes frameshift. Duplication - one or more bases are repeated -> leads to frameshift. Inversion - group of bases separate from DNA sequence and rejoin at same position but in reverse order -> forms different amino acids and therefore protein. Translocation - group of bases separate from DNA sequence on 1 chromosome and insert into DNA sequence of another chromosome -> different proteins formed. Some mutations have no effect (neutral) e.g. occurs on non coding part of DNA or silent mutation