...
- VVS: GTG GTC TCC -> GTG GTG TCC
- GTC frequency: 0.24
- GTG frequency: 0.47
If you really care, you can mutate these sites back using site-directed mutagenesis (e.g. this kit: http://www.genomics.agilent.com/en/Site-Directed-Mutagenesis/QuikChange-Lightning/?cid=AG-PT-175&tabId=AG-PR-1162)