IVS means InterVening Sequence (i.e. an intron). Your mutation is located in the gene you are studying, in the first intron, five nucleotides before the consensus intron site AG.
You might give a look here for further details (http://www.hgvs.org/mutnomen/history-1996.html). I paste the sentence about IVS below for reference. Intron mutations when the full genomic sequence is not known can be designated by the intron (IVS) number, positive numbers starting from the G of the donor site invariant GT, negative numbers starting from the G of the acceptor site invariant AG. IVS4+1G>T denotes the G to T substitution at nt +1 of intron 4. IVS4-2A>C denotes the A to C substitution at nt -2 of intron 4. When the full length genomic sequence is known, the mutation can also be simply designated by the nt number of the reference sequence.
You can search for your gene of interest in Ensembl, then have a look at the intronic variations either using the variation table (showing all variations for a gene) and choosing 'intronic'
then pay attention to the coordinate to determine which falls in your first intron.
Or, you can go to the Location view for your gene of interest and zoom in to the first intron of your gene. Turn on the variation track and see what overlaps your position of interest:
I hope that helps.
Good question - trying to convert a common name of a genetic variant into a standard ID.
This sounds a lot like a rather generic name for an insertion/deletion variant. You could check the Database of Genomic Variants but I doubt it is there. So, I would suggest that you carefully read the Methods section of the articles in which this variant is studied, keeping in mind that you may have to reconstruct electronically the PCR and other protocols used to detect the variant.
In the end, you may find that there is no rs#.
Please reply if you need more help as this is something we have done a lot in our group.
Fabio gives a good answer +1. However, one must still check the Methods because what those authors thought was 5 bases away from teh splice site may not be according to corrected gene models. I once studied a SNP that was called a promoter SNP that was later placed in an intron by the corrected gene model. So, I map the variant to the reference genome and cross-check with dbSNP entries to be 100% certain of the SNP ID.