Silent mutations or synonymous mutations are DNA mutations that, although they alter a particular codon, they do not alter the final amino acid, and hence do not affect the final protein. Because silent mutations do not alter protein function they are thought to be evolutionarily neutral.
However anaylsis of mutations in genes causing genetic disorders has shown that silent mutations can affect gene transcription, leading to the formation of truncated protein with reduced or no function.
References
- Chao H.K., Hsiao K.J., and Su T.S. 2001. A silent mutation induces exon skipping in the phenylalanine hydroxylase gene in phenylketonuria. Human Genetics 108(1):14-9
- Monteraa, M. el al. 2001. A silent mutation in exon 14 of the APC gene is associated with exon skipping in a FAP family. Journal of Medical Genetics 38:863-867
