[ensembl-dev] variation synonyms

[Andrea Edwards]

Happy New Year esteemed bioinformaticians

I have a question about variation synonyms

As you know, ensembl variation database has the concept of variation 
synonyms where, as the name suggests, database entries from different 
(or the same) source represent the same sequence variations and so the 
ids from the different sources are synonyms for the variation. However 
when i look at some snps and their synonyms i don't understand the why 
they are considered to be the same snp. I am only looking at snps and 
not other variants.

Example 1

Variation_id in ensembl (e!60_37e) = 2092683
variation name = dbSNP id  = rs43654637
This variation maps to 11[1955348] in dbSNP(v131) and ensembl (i.e. 
there is a variation feature for this variation at 11[1955348])

There is one synonym for this snp. This synonym is in dbSNP with the id 
rs43654640 and genome mapping in dbSNP = 11[1955248])

The synonym maps to a different genome location (but i appreciate a 
variation in ensembl is defined by its location). Also the flanking 
sequence of rs4365460 is also different to rs43654637.Why are these 2 
snps classed as synonyms?

thanks a lot