I have a list of SNPs as a GWAS result and I would like add the information whether a SNP is a known eQTL according to GTEx (and the respective tissue) to each of the entries of this list. This seems to me like a common problem, but somehow I cannot find a "direct way" to do this. If I check a single SNP rsID on the GTEx site, they provide a table with the respective gene, p value, effect size and tissue, which is exactly what I was looking for, but there seems to be no way to get the information for a whole list of SNPs.
On the NCBI Phenotype-genotype integrator website it is written, that the GTEx information is part of the output, but when I upload a list of SNPs, I obtain eQTL data only for very few SNPs and when I checked single SNPs for which data is available on the GTEx portal, their eQTL data is not included in the Phenotype-genotype integrator output.
How can I obtain this information? Is there any portal/program which makes the data easily accessible just by giving a list of SNP ids or SNP positions as input? Do I have to apply for data access at dbGaP? If I need access via dbGaP, what would be the recommended way to process the data?
Thank you for your help!