From SNPedia
| Geno
|
Mag
|
Summary
|
| (A;A)
|
0
|
normal
|
| (A;G)
|
2.5
|
stronger cravings for alcohol. if alcoholic, naltrexone treatment 2x more successful
|
| (G;G)
|
2.6
|
more pain
|
| ? | (A;A) (A;G) (G;G) | 28 |
|---|
 |
The
rs1799971(G) allele in exon 1 of the mu opioid receptor
OPRM1 gene causes the normal amino acid at residue 40, asparagine (Asn), to be replaced by aspartic acid (Asp). In the literature this SNP is also known as A118G, N40D, or Asn40Asp.
Carriers of at least one rs1799971(G) allele appear to have stronger cravings for alcohol than carriers of two rs1799971(A) alleles, and are thus hypothesized to be more at higher risk for alcoholism. [PMID 17207095]
However, subsequent research results are mixed, and there are other studies both agreeing or disagreeing with this finding [PMID 15525999, PMID 9399694, PMID 12960749]
Among 200+ alcoholics treated with naltrexone, rs1799971(G) carriers receiving the drug (even without behavioral intervention) had an increased percentage of days abstinent (p = .07) and a decreased percentage of heavy drinking days (p = .04) if treated with naltrexone vs. placebo, whereas rs1799971(A;A) homozygotes showed no medication differences. Upon treatment with naltrexone, 87% of rs1799971(G) carriers had a good clinical outcome, compared with only 55% of individuals with the (A;A) genotype (odds ratio, 5.75, CI: 1.88-17.54)[PMID 18250251]
This SNP may also influence the response to opioids such as heroin, codeine or morphine.
A study of 200 Chinese heroin addicts found increased frequency for the rs1799971(G) allele compared to non-addicts (40% vs 29%) [PMID 11338173]; but another study of Han Chinese addicts found no difference [PMID 11933204].
spittoon Alcoholism related
- rs1799971(A;A) severe alcoholism 2x
- rs1799732(I;I) severe alcoholism 1.85x
[PMID 19860800] Initial Evidence of an Association Between OPRM1 and Adolescent Alcohol Misuse
| PharmGKB | PA165110399 |
| Name | OPRM1: A118G |
| Annotation | Risk or phenotype-associated allele(s): AG/GG. Phenotype: The G118 SNP (AG/GG) was associated with a 27% increase in plasma alfentanil concentration (P=0.034), a 54% increase in alfentanil dose (P=0.009). Despite the increased alfentanil self-administration, the G118 SNP was associated with a 52% increase in verbal analogue pain scores over the same period of time (P=0.047). Study size: 99. Study population/ethnicity: patients with acute pain. |
| Gene | OPRM1 |
| Featue | |
| Evidence | PubMed ID:19605407 |
| Drugs | alfentanil |
| Diseases | Pain |
| Curation Level | Curated |
[PMID 20112002] A118G Polymorphism of OPRM1 Gene is Associated with Schizophrenia
| PharmGKB | PA161748324 |
| Name | OPRM1: A118G |
| Annotation | Based on a study at 207 patients treated with morphine, carriers of OPRM1 GG genotype required 93% higher morphine dose compared to carriers of AA genotypes (p = 0.012). |
| Gene | OPRM1 |
| Featue | |
| Evidence | PubMed ID:17156920 |
| Drugs | morphine |
| Diseases | Pain |
| Curation Level | Curated |
| PharmGKB | PA162191297 |
| Name | OPRM1: A118G, Asn40Asp |
| Annotation | Several studies found an enhanced cortisol response to naloxone among subjects with the Asp40 variant. A study in healthy individuals who were of European Americans or Asian ancestry found that participants with one or two Asp40 alleles had a significantly greater cortisol response to naloxone than Asn40 homozygotes, but the effect was limited to European Americans. |
| Gene | OPRM1 |
| Featue | |
| Evidence | PubMed ID:11751037; PubMed ID:12627468; PubMed ID:18004207 |
| Drugs | naloxone |
| Diseases | |
| Curation Level | Curated |
| PharmGKB | PA162360620 |
| Name | OPRM1: A118G, Asn40Asp |
| Annotation | This variant is associated with increased receptor affinity, alcohol-induced euphoria, and risk for alcohol use disorders. Alcoholic subjects with an Asp40 allele tend to have better clinical outcomes ( increased percentage of days abstinent and decreased percentage of heavy drinking days) when treated with naltrexone for alcoholism compared to those with the Asn40/Asn40 genotype. |
| Gene | OPRM1 |
| Featue | |
| Evidence | PubMed ID:15525999; PubMed ID:15608594; PubMed ID:17339526; PubMed ID:18250251; PubMed ID:8072460 |
| Drugs | ethanol, naltrexone |
| Diseases | Alcoholism |
| Curation Level | Curated |
[PMID 21277709] No evidence of association between 118A>G OPRM1 polymorphism and heroin dependence in a large Bulgarian case-control sample
[PMID 21160491] Haplotype block structure of the genomic region of the mu opioid receptor gene
[PMID 22046326] 'Smoking Genes': A Genetic Association Study
[PMID 22071118] Ethnic-specific meta-analyses of association between the OPRM1 A118G polymorphism and alcohol dependence among Asians and Caucasians
