[ensembl-dev] why does ensembl have multiple dbSNP records for the same locus

[Andrea Edwards]

Hi

I have written a program to get all of the cow snps from ensembl present 
in dbSNP. When i examine these snps i find some chromosome loci have 
multiple dbSNP records. In other words if i do something like

select count(*) distinct chromosome, locus from snps

i get less than the total number of snps obtained


Why is this? Is this something to do with ensembl or dbSNP. I thought 
dbSNP merged all submitter records (ss) into one rs record for each 
chromosome locus. So i was expecting one dbSNP record per snp. I thought 
perhaps it might a representation of the snp in a different database but 
i have been informed that the only variations for cow in ensembl are 
from dbSNP.

thanks a lot