OPRM1A118G, a functional human mu-opioid receptor (MOR) polymorphism, is associated with drug dependence and altered stress responsivity in humans as well as altered MOR signaling.
The evidence of interactions between NOP and μ-opioid receptor (MOPr) receptors has been exploited in the use of mixed NOPr/MOPr modulators as analgesics and in the treatment of drug addiction.
Synthetic and Receptor Signaling Explorations of the Mitragyna Alkaloids: Mitragynine as an Atypical Molecular Framework for Opioid Receptor Modulators.
A single-nucleotide polymorphism (SNP) within the OPRM1 gene, A118G, leading to an amino acid change (Asn40Asp) in the extracellular portion of the receptor, has been implicated in alcoholism as well as in drug addiction, pain sensitivity and stress response, and in animal and human studies relates to the alcohol-dependent phenotype as well as to the treatment response to the µ-opioid antagonist naltrexone.
In the present study, we aimed to evaluate the role of 14 polymorphisms in 8 candidate genes potentially relevant for drug addiction (OPRM1, DRD2, DBH, COMT, BDNF, SLC6A4, 5HT2A, and SLC1A2) as predictors for detoxification outcome of MOH patients at 2 months of follow-up.
Many genetic variations have been identified in the human µ-opioid receptor MOP gene (OPRM1), and their implications have been reported in the effects of opioid drugs and susceptibility to drug dependence.
A common single nucleotide polymorphism (SNP), A118G, in the mu-opioid receptor gene can affect opioid function and, consequently, has been suggested to contribute to individual variability in pain management and drug addiction.
A single nucleotide polymorphism (SNP) in the human mu-opioid receptor gene (OPRM1A118G) has been widely studied for its association in a variety of drug addiction and pain sensitivity phenotypes; however, the extent of these adaptations and the mechanisms underlying these associations remain elusive.
Although none of the SNPs achieved genome-wide association significance levels (defined as p<.000001), two genes probed with multiple SNPs (OPRM1 and CHRNA2) emerged as plausible candidates for a role in antisocial drug dependence after gene-based permutation tests.
Increasing evidence suggests that differences in Oprm1 gene sequences affect the amount of Oprm1 mRNA and sensitivity to opiates, and >100 polymorphisms have been identified in the human OPRM1 gene, some of which are related to vulnerability to drug dependence in some populations.
Genetic variants of OPRM1 have been implicated in predisposition to drug addiction, in particular the single nucleotide polymorphism A118G, leading to an N40D substitution, with an allele frequency of 10-32%, and uncertain functions.
Consequently, the present study examined the association of a polymorphic (CA)n repeat at the OPRM1 locus (the gene coding for the mu opioid receptor) to alcohol or drug dependence in 320 Caucasian and 108 African-American substance-dependent or control subjects.
OPRM1 alleles, genotypes and haplotypes from three psychiatrically characterized population samples (US Caucasian [USC, n=100], Finnish Caucasian [FC, n=324] and Southwestern American Indian [SAI, n=367]), were used to perform association and sib-pair linkage analyses with alcohol and drug dependence diagnoses.