OPRM1
Chr 6opioid receptor mu 1
Also known as: LMOR, M-OR-1, MOP, MOR, MOR1, OPRM
The mu opioid receptor encoded by this gene serves as the principal target for endogenous opioid peptides like beta-endorphin and enkephalins, as well as synthetic opioids including morphine and fentanyl, functioning as a G-protein-coupled receptor that regulates pain sensitivity, reward pathways, and drug dependence. Mutations in OPRM1 are associated with variations in opioid and alcohol addiction susceptibility and altered pain sensitivity, though the causal relationship remains unclear. This gene is not highly constrained against loss-of-function mutations (pLI near zero), and inheritance patterns for addiction susceptibility variants appear to follow typical Mendelian patterns.
Some data sources returned errors (1)
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Population Genetics & Constraint
gnomAD v4 — loss-of-function & missense intolerance
Highly tolerant — LoF variants common in population
Tolerant to missense variation
This gene has evidence for multiple mechanisms of pathogenicity (gain-of-function and dominant-negative). Both the Badonyi & Marsh prediction and the broader genomic evidence point to gain-of-function as the predominant mechanism. Different variants in this gene may act through different mechanisms — interpret in context of the specific variant.
Note: In-silico variant effect predictors (SIFT, PolyPhen, REVEL, CADD) may underestimate pathogenicity of missense variants in genes with GOF or DN mechanisms. Consider functional evidence and clinical context.
Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.
ClinVar Variant Classifications
139 submitted variants in ClinVar
Classification Summary
Curated Variants Distribution
Classified variants from ClinVar · 5 ACMG categories
| Classification | LoF | Missense + Inframe | Non-coding | Synonymous | Total |
|---|---|---|---|---|---|
Pathogenic | 0 | 0 | 24 | 0 | 24 |
Likely Pathogenic | 0 | 0 | 3 | 0 | 3 |
VUS | 0 | 83 | 4 | 0 | 87 |
Likely Benign | 0 | 8 | 0 | 4 | 12 |
Benign | 1 | 2 | 1 | 1 | 5 |
| Total | 1 | 93 | 32 | 5 | 131 |
LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly
View in ClinVar →Protein Context — Lollipop Plot
OPRM1 · protein map & ClinVar variants
Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.
3D Protein StructureAlphaFold
External Resources
Links to major genomics databases and tools
Clinical Trials
Active and recruiting trials from ClinicalTrials.gov
Predicting and Preventing Adverse Maternal and Child Outcomes of Opioid Use Disorder in Pregnancy
RECRUITINGEfficacy of a Prediction Model-based Algorithm to PREVENT Drug-induced Impulse Control Disorders in Parkinson's Disease
NOT YET RECRUITINGHome-based Transcranial Direct Current Stimulation (tDCS) Compared to Duloxetine: Non-inferiority Clinical Trial (FIBROSTIM)
RECRUITINGPersonalized Perioperative Analgesia Platform (PPAP) for Pediatric Spine Fusion Surgery (sIRB)
RECRUITINGParaphilic Disorders and Other Conditions With Risk for Sexual Violence: a Case-control Study
RECRUITINGElectroacupuncture Therapy in Reducing Chronic Pain in Patients After Breast Cancer Treatment
ACTIVE NOT RECRUITINGHIIT vs MICT During Pregnancy and Health and Birth Outcomes in Mothers and Children
RECRUITINGPrecision Analgesia for Cardiac Surgery
NOT YET RECRUITINGExternal Resources
Links to major genomics databases and tools