The A118G SNP in the human OPRM1 gene has been studied intensely and implicated in a variety of disease states and treatment responses. In particular, alterations in receptor function resulting from this SNP are believed to contribute to the susceptibility for developing drug dependence. The strongest evidence for a beneficial effect of the A118G polymorphism stems from studies evaluating the response to naltrexone for alcohol and nicotine consumption, highlighting the importance of pharmacogenetics when devising treatment options to determine who may be more likely to benefit from a given therapy. In addition to choosing treatment options, understanding the mechanisms underlying these beneficial effects may allow us to develop therapies for individuals with the common A118 allele.
