AOC1

Chr 7

amine oxidase copper containing 1

Also known as: ABP, ABP1, DAO, DAO1, KAO, KDAO

NCBI Gene: 26ENSG00000002726UniProt: P19801

This gene encodes a metal-binding membrane glycoprotein that oxidatively deaminates putrescine, histamine, and related compounds. The encoded protein is inhibited by amiloride, a diuretic that acts by closing epithelial sodium ion channels. Alternatively spliced transcript variants encoding multiple isoforms have been observed for this gene. [provided by RefSeq, Jan 2013]

194
ClinVar variants
70
Pathogenic / LP
0.00
pLI score
3
Active trials
Clinical Summary— AOC1
⚡
Population Constraint (gnomAD)
Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.
📋
ClinVar Variants
70 Pathogenic / Likely Pathogenic· 113 VUS of 194 total submissions
💊
Clinical Trials
3 active or recruiting trials — potential therapeutic options may be available

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

gnomAD
Tolerant — LoF & missense variants common in population
LoF Constraint?LOEUF (Loss-of-function Observed/Expected Upper bound Fraction) is the upper bound of the 90% CI for LoF OE — the preferred gnomAD v4 metric. Lower = more intolerant to LoF. LOEUF < 0.35 = highly constrained.
0.97LOEUF
pLI 0.000
Z-score 1.68
OE 0.63 (0.42–0.97)
Tolerant

Typical tolerance to LoF variation

Missense Constraint?Missense Z-score: standard deviations fewer missense variants observed vs. expected. Z > 3.09 (p < 0.001) = gene does not tolerate missense variation. OE missense < 0.6 is also considered constrained.
0.76Z-score
OE missense 0.90 (0.83–0.98)
428 obs / 474.5 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios?Shaded band = 90% confidence interval. Vertical tick = point estimate. Grey threshold line = gnomAD constraint cutoff for that variant class.
LoF OE?Ratio of observed to expected LoF variants. Upper CI bound (LOEUF) ≤ 0.35 = strong LoF constraint signal.0.63 (0.42–0.97)
0≤0.351.4
Missense OE?Ratio of observed to expected missense variants. OE ≤ 0.6 = fewer missense variants than expected by chance.0.90 (0.83–0.98)
0≤0.61.4
Synonymous OE?Control metric — synonymous variants are largely neutral and expected near OE = 1.0. Significant deviation may indicate annotation issues.0.94
0≤1.21.6
LoF obs/exp: 15 / 23.8Missense obs/exp: 428 / 474.5Syn Z: 0.68

ClinVar Variant Classifications

194 submitted variants in ClinVar

ClinVar

Classification Summary

Pathogenic66
Likely Pathogenic4
VUS113
Likely Benign9
Benign1
Conflicting1
66
Pathogenic
4
Likely Pathogenic
113
VUS
9
Likely Benign
1
Benign
1
Conflicting

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

ClassificationLoFMissense + InframeNon-codingSynonymousTotal
Pathogenic
0
0
66
0
66
Likely Pathogenic
0
0
4
0
4
VUS
0
104
9
0
113
Likely Benign
0
6
1
2
9
Benign
0
1
0
0
1
Conflicting
—1
Total0111802194

LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly

View in ClinVar →

Protein Context — Lollipop Plot

AOC1 · protein map & ClinVar variants

Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.

OMIM — Genotype-Phenotype Relationships

1 OMIM entry

OMIM
Clinical Literature
Landmark / reviewRecent case evidence
Key Publications
Landmark & review papers · by relevance
PubMed
Strikingly conserved gene expression changes of polyamine regulating enzymes among various forms of acute and chronic kidney injury.
Sieckmann T et al.·Kidney Int
2023
Identification and Validation of Tryptophan Metabolism-Related Genes in Diabetic Kidney Disease and Construction of a Clinical Prediction Model.
Liu S et al.·J Diabetes Res
2025Functional
m6A-enriched lncRNA LINC00839 promotes tumor progression by enhancing TAF15-mediated transcription of amine oxidase AOC1 in nasopharyngeal carcinoma.
Zheng WH et al.·J Biol Chem
2023
Comment on "Impact of AOC1 and HNMT Variants on the Therapeutic Outcomes of a Histamine Reducing Diet in Autism Spectrum Disorder".
Raza R et al.·J Mol Neurosci
2025
Population-based high-dimensional analyses identify multiple intrinsic characters for cancer vaccines against lung squamous cell carcinoma.
Zeng L et al.·Med Oncol
2024
Diamine oxidase acts as a novel risk factor in abnormal inflammation via mediating "cytosolic ROS-autophagy-IFN-γ" axis in NK cells.
He D et al.·Life Sci
2025
The Prevalence of Single Nucleotide Polymorphisms of the AOC1 Gene Associated with Diamine Oxidase (DAO) Enzyme Deficiency in Healthy Newborns: A Prospective Population-Based Cohort Study.
Fortes Marin E et al.·Genes (Basel)
2025Cohort
Integrated proteomics and metabolomics reveal variations in pulmonary fibrosis development and the potential therapeutic effect of Shuangshen Pingfei formula.
Chen Y et al.·J Ethnopharmacol
2023
Two new cases of interstitial 7q35q36.1 deletion including CNTNAP2 and KMT2C.
Tosca L et al.·Mol Genet Genomic Med
2021Case report
Pilot Study on the Prevalence of Diamine Oxidase Gene Variants in Patients with Symptoms of Histamine Intolerance.
Duelo A et al.·Nutrients
2024Cohort
Top 10 resultsSearch PubMed ↗
Recent Gene-Specific Literature
Gene in title · MEDLINE · newest first
Europe PMC
Top 5 resultsSearch Europe PMC ↗

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

ClinicalTrials.gov
SymbioticUremic ToxinsGut -Microbiota

Modulation of Gut Microbiota Composition and Gut Permeability Profiles by Multispecies Synbiotic Supplementation in Hemodialysis Patients

NOT YET RECRUITING
NCT07461233Phase NATungs' Taichung Metroharbour HospitalStarted 2026-04-01
Multispecies Synbiotic Supplementation
Gastrointestinal Dysfunction-induced Enteral Nutrition Intolerance

Efficacy of Fecal Microbiota Transplantation in ICU Patients With Gastrointestinal Dysfunction-induced Enteral Nutrition Intolerance

RECRUITING
NCT06603883Phase PHASE2, PHASE3Union Hospital, Tongji Medical College, Huazhong University of Science and TechnologyStarted 2024-10-19
Fecal microbiota transplantation (FMT) by nasal jejunal tube
Pregnancy Complications

Diamine Oxidase and Adverse Pregnancy Outcomes

RECRUITING
NCT06281366Hospital Universitari Vall d'Hebron Research InstituteStarted 2024-02-16

External Resources

Links to major genomics databases and tools