Table 2.
Comparison of CSN and current nomenclature for exonic base substitutions
| CSN | Current nomenclaturea | |
|---|---|---|
| Nucleotide | Amino acid | |
| c.1040A>G_p.Gln347Arg | c.1040A>G | p.Gln347Arg |
| c.1911T>C_p.= | c.1911T>C | p.Gly637Gly |
| c.3264T>C_p.= | c.3264T>C | p.Pro1088Pro |
| c.3515C>T_p.Ser1172Leu | c.3515C>T | p.Ser1172Leu |
| c.3516G>A_p.= | c.3516G>A | p.Ser1172Ser |
| c.5682C>G_p.Tyr1894X | c.5682C>G | p.Tyr1894Ter |
| c.5855T>A_p.Leu1952X | c.5855T>A | p.Leu1952Ter |
| c.6131G>T_p.Gly2044Val | c.6131G>T | p.Gly2044Val |
| c.6675A>G_p.= | c.6675A>G | p.Thr2225Thr |
| c.7558C>T_p.Arg2520X | c.7558C>T | p.Arg2520Ter |
| c.8182G>A_p.Val2728Ile | c.8182G>A | p.Val2728Ile |
| c.9976A>T_p.Lys3326X | c.9976A>T | p.Lys3326Ter |
CSN allows easy visual discrimination between the different classes of exonic base substitutions with ‘=’ denoting a synonymous variant, ‘X’ denoting a stop-gain variant and the three letter code of the new amino acid denoting a nonsynonymous variant. CSN includes both the nucleotide and amino acid level descriptions to give a single, unique identifier for each variant.
aThe current nomenclature given is one of several different notation systems currently in use