As guardian of the HGVS recommendations for the description of sequence variants I have
received the request to indicate how to describe modifications of DNA, RNA and
protein molecules. The most pressing are those to describe RNA editing and
My suggestion for RNA editing, now open for comments, is to describe this as;
So, for a nucleotide edited at RNA level on DNA describe it by adding a "@"
to the position.
Based on the current recommendations the descriptions on DNA level could be g.= / c.= because nothing changes. The change is only at RNA and potentially protein level. The reason to suggest a specific description at DNA level is to make it easier to retrieve information on RNA editing from databases;
RNA editing is not of one type and the change r.143c>u is probably not correct
because the 'c' is not really changed to a 'u'. At some point we probably need to suggest
ways to exactly describe the modification that was found but I believe we can do that
later. Making such recommendations can then be combined with those for DNA modifications
(like methylation with methyl or hydroxy-methyl groups) making sure they follow the same
The use of the '@' character versus other characters (&, $, ~, #) is of course debatable. Another option is to use a three-letter abbreviation like 'del' and 'ins', e.g. edt (g.1287edt / c.143edt) but this is seems less attractive (longer and potentially confusing). The '@' is just there like a short footnote, indicating, 'note this site, something is happening at ('@') this position.
Johan den Dunnen
Human Genome Variation Society
mail to: ddunnen @ HumGen.nl