Covered this topic on my blog (
here) based on a recent paper on the
OPRM1 gene, which is implicated in a key opioid receptor (original article
here).
The "main" SNP (or at least the one with the greatest amount of research weight behind it) is rs1799971. The G allele is associated with increased pain sensation. A lot of the other SNPs shown in the article aren't covered by 23andMe (v2).
Pain sensitivity is (at the least) a polygenetic trait, so your status per this SNP doesn't necessarily have to match your phenotype.
I'm AA at rs1799971 (no increased pain sensation). How does everyone else stack up on this SNP?