Hi, 

I can't retrieve the flanking regions of my snps.

I used:

snpmart<- useMart("ENSEMBL_MART_SNP",dataset = "hsapiens_snp")

TEST<- getBM(attributes = c("refsnp_id","upstream_flank","downstream_flank"), filters = c("snp_filter","upstream_flank","downstream_flank"), checkFilters = FALSE, values = list(proxy_list,20,20), mart = snpmart)

where proxy_list is a list of several snps

and it gave me this error:

Error in getBM(attributes = c("refsnp_id", "upstream_flank", "downstream_flank"),  : 
  Query ERROR: caught BioMart::Exception: non-BioMart die(): Can't use an undefined value as an ARRAY reference at /ensemblweb/wwwmart/www_86/biomart-perl/lib/BioMart/Dataset/GenomicSequence.pm line 396.

sessionInfo()

R version 3.3.2 (2016-10-31)
Platform: x86_64-pc-linux-gnu (64-bit)
Running under: Ubuntu 16.04.1 LTS

Hope you can help me out

cheers, 

ana

This is all very opaque, but you don't need to specify that you want to retrieve the flanking sequences in the attributes arguments.  However you do need to include something called 'snp' which will contain both the variant in question and the sequence on each side.  This code gives an example for two SNPs.

snp_list <- list("rs25", "rs16944")

snp_sequence <- getBM(attributes = c("refsnp_id", "snp"), 
                filters = c("snp_filter", "upstream_flank", "downstream_flank"), 
                checkFilters = FALSE, 
                values = list(snp_list, 20, 20), 
                mart = snpmart, 
                bmHeader = TRUE)

> snp_sequence
                               Variant sequence Variant Name
1 TGGGTGCTGTTCTCTGCCTC%A/G%GGAGCTCTCTGTCAATTGCA      rs16944
2 ACTATCAAATTCCAATTGCA%T/C%AGGATTGCATGCAGAAGCTC         rs25

I'll take a look at adding this example to the vignette, since I couldn't find any working examples of how to do this in the documentation.