# Find rsIDs for GRCh37 SNPs and rsIDs for GRCh38 SNPs and compare for overlap

I have a long list of variant IDs that I generated as a result of research done one GRCh37 genomes (e.g. 13_28025615_G_C_b37). I want to get their rsIDs and compare them to a newly-obtained list of GRCh38 rsIDs that have also been retrieved from similarly formatted variant IDs (e.g. chr22_50473581_G_A_b38). How would I go about doing this? I've tried installing biomaRt as a package but I can't quite make heads or tails of it and it's not clear to me that it would support both versions of genome builds.

• When I do that, the only datasets I can see with listDatasets(snpmart) are GRCh38.p10. – CelineDion Sep 23 '19 at 19:47