Synonyms for Mutation (same or very similar meaning)
WordNet sense 1 ((biology) an organism that has characteristics resulting from chromosomal alteration):
mutant, sport, variation
WordNet sense 2 ((genetics) any event that changes genetic structure; any alteration in the inherited nucleic acid sequence of the genotype of an organism):
chromosomal mutation, genetic mutation
From the ODE community, based on WordNet
add/edit