I have heard of this...but up until recently I believe it was cost prohibitive...at least here in the states.
Now however, I believe that in some cases the testing is covered, so it is definitely worth asking about
!http://genelex.com/patients/
Here is one example of a company that offers this testing:
http://genelex.com/patients/
Best wishes on your best Rx quest...hope this give you some good direction!
S.C.