Hello,

Are there any bioconductor R packages or functions that would allow me to map a SNP to all genes within 50kb (upstream or downstream) of the SNP?

Thanks

Yes. You could use the relevant TxDb package to get the gene locations (say in a GRangesList or GRanges), create a GRanges that defines a 100 kb range centered on your SNP and then use e.g., subsetByOverlaps to subset the genes to just those that are overlapped by your 100kb range. The relevant packages are GenomicAlignments and GenomicFeatures, both of which have vignettes you could read.