Mutations
Mutations are changes in the nucleotide sequence of the DNA as compared with a wild type sequence.
Mutations are categorized according to how they change the order of bases:
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Substitution: one base is replaced by another
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Deletion: one or more bases are deleted
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Insertions: one or more bases are inserted
Mutations in coding sequences are categorized according to their effect on the protein:
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Synonymous or silent mutation: a substitution that does not change the amino acid
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Non-synonymous or missense mutation: a substitution that changes the amino acid
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Nonsense mutation: generates a stop codon
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Frameshift mutation: insertion or deletion not divisible by 3 that alters the reading frame