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OPRM1

Opioid receptor mu 1

Gene Number: 4988

Location: 6q25.2

Key Functions: Pain perception, opioid response, reward system regulation, addiction susceptibility, mood modulation


OPRM1 encodes the μ-opioid receptor (MOR), a G protein–coupled receptor (GPCR) that serves as the primary molecular target for endogenous opioid peptides (such as endorphins and enkephalins) and exogenous opioid drugs (such as morphine, fentanyl, and heroin). The receptor plays a central role in mediating the effects of both naturally occurring and pharmacological opioids on analgesia, reward, mood regulation, and stress adaptation.

SNP ID
Your Genotype
Alt Allele
Interpretation
rs1799971
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G
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rs9479757
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A
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rs1799971 (A118G)

  • AA – Normal risk; baseline for pain sensitivity and addiction phenotypes (R).

  • AG – ~2.5× stronger cravings for alcohol; among alcohol-dependent individuals, naltrexone is ~2× more effective (R).

  • GG – Higher pain sensitivity (e.g., need more morphine post-surgery) and higher social rejection sensitivity (R).

Functional effect: The G allele (Asp40) may reduce MOR-1 expression and glycosylation, alter β-endorphin affinity, and influence opioid response and addiction behaviors.


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