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From SNPedia

Geno Mag Summary
(A;A) 4 Asian Flusher; increased risk of esophageal cancer; East Asian ancestry; Disulfiram not effective for alcoholism.
(A;G) 3.5 Asian Flush; worse hangovers; increased risk of esophageal cancer; East Asian ancestry; Disulfiram probably not effective for alcoholism.
(G;G) 2 Alcohol Flush: Normal, doesn't flush. Normal hangovers. Normal risk of Alcoholism. Normal risk of Esophageal Cancer. Disulfiram is effective for alcoholism.
ReferenceGRCh38 38.1/141
is asnp
is mentioned by
1000 genomesrs671
23andMe allrs671
SNP Nexus

GWAS Ctlgrs671
Max Magnitude4
? (A;A) (A;G) (G;G) 28
rs671 is a classic SNP, well known in a sense through the phenomena known as the "alcohol flush", also known as the "Asian Flush" or "Asian blush", in which certain individuals, often of Asian descent, have their face, neck and sometimes shoulders turn red after drinking alcohol.[PMID 6582480OA-icon.png]

The rs671(A) allele of the ALDH2 gene is the culprit, in that it encodes a form of the aldehyde dehydrogenase 2 protein that is defective at metabolizing alcohol. This allele is known as the ALDH*2 form, and individuals possessing either one or two copies of it show alcohol-related sensitivity responses including facial flushing, and severe hangovers (and hence they are usually not regular drinkers). Perhaps not surprisingly they appear to suffer less from alcoholism and alcohol-related liver disease. [PMID 511165, PMID 16046871]

Disulfiram (Antabuse) is probably an ineffective treatment for alcohol dependence in people who have the Asian Flush.

Tests for the alcohol flush reaction at deCODEme are based on rs671.

23andMe blog carriers of the A allele are prone to esophageal cancer, which is also known as upper aerodigestive tract (UAT) cancer, due to acetaldehyde from smoking.


[PMID 19698717] Functional variants in ADH1B and ALDH2 coupled with alcohol and smoking synergistically enhance esophageal cancer risk

[PMID 19706845] A Novel Polymorphism rs1329149 of CYP2E1 and a Known Polymorphism rs671 of ALDH2 of Alcohol Metabolizing Enzymes Are Associated with Colorectal Cancer in a Southwestern Chinese Population

[PMID 20093384] Impact of smoking on lung cancer risk is stronger in those with the homozygous aldehyde dehydrogenase 2 (ALDH2) null allele in a Japanese population

[PMID 19641380OA-icon.png] Candidate gene polymorphisms for diabetes mellitus, cardiovascular disease and cancer are associated with longevity in Koreans

GWAS snp
PMID [PMID 20139978]
Trait Hematological and biochemical traits
Title Genome-wide association study of hematological and biochemical traits in a Japanese population
Risk Allele A
P-val 7E-10
Odds Ratio 0.26 [NR] % variance

[PMID 20833657] Strong interaction between the effects of alcohol consumption and smoking on oesophageal squamous cell carcinoma among individuals with ADH1B and/or ALDH2 risk alleles

[PMID 21372407] Confirmation of ALDH2 as a Major Locus of Drinking Behavior and of Its Variants Regulating Multiple Metabolic Phenotypes in a Japanese Population

[PMID 21476199] Acetaldehyde dehydrogenase 2 SNP rs671 and susceptibility to essential hypertension in Mongolians: a case control study

[PMID 22102315OA-icon.png] Strong protective effect of the aldehyde dehydrogenase gene (ALDH2) 504lys (*2) allele against alcoholism and alcohol-induced medical diseases in Asians

GWAS snp
PMID [PMID 22171074]
Title A genome-wide association and gene-environment interaction study for serum triglycerides levels in a healthy Chinese male population.
Risk Allele
P-val 0.000002
Odds Ratio None None
GWAS snp
PMID [PMID 21971053OA-icon.png]
Title Genome-wide association study of coronary artery disease in the Japanese.
Risk Allele A
P-val 2E-34
Odds Ratio 1.4300 [1.35-1.51]
GWAS snp
PMID [PMID 22286173]
Title Genome-wide association study for intracranial aneurysm in the Japanese population identifies three candidate susceptible loci and a functional genetic variant at EDNRA.
Risk Allele C
P-val 0.000003
Odds Ratio 1.2400 None

[PMID 22508505] Aldehyde-stress resulting from Aldh2 mutation promotes osteoporosis due to impaired osteoblastogenesis

[PMID 22551939] Association of a functional single-nucleotide polymorphism in the ALDH2 gene with essential hypertension depends on drinking behavior in a Chinese Han population

Risk rs671(A;A)
Alt rs671(A;A)
Reference rs671(G;G)
Significance Other
Disease Acute alcohol sensitivity Alcohol dependence Susceptibility to hangover Sublingual nitroglycerin Esophageal cancer
Variation info
Gene ALDH2
CLNDBN Acute alcohol sensitivity Alcohol dependence Susceptibility to hangover Sublingual nitroglycerin, susceptibility to poor response to Esophageal cancer, alcohol-related, susceptibility to
Reversed 0
HGVS NC_000012.11:g.112241766G>A
CLNSRC OMIM Allelic Variant
CLNACC RCV000020058.2, RCV000020059.2, RCV000020060.2, RCV000020061.2, RCV000020062.2,

[PMID 18317873] Statistical analysis of the associations between polymorphisms within aldehyde dehydrogenase 2 (ALDH2), and quantitative and qualitative traits extracted from a large-scale database of Japanese single-nucleotide polymorphisms (SNPs).

[PMID 18331377OA-icon.png] Association of ADH and ALDH genes with alcohol dependence in the Irish Affected Sib Pair Study of alcohol dependence (IASPSAD) sample.

[PMID 18996923OA-icon.png] Associations of ADH and ALDH2 gene variation with self report alcohol reactions, consumption and dependence: an integrated analysis.

[PMID 19041386OA-icon.png] Genetic-epidemiological evidence on genes associated with HDL cholesterol levels: a systematic in-depth review.

[PMID 19262484] Gene-environmental interaction regarding alcohol-metabolizing enzymes in the Japanese general population.

[PMID 20417517] The ALDH2 Glu504Lys polymorphism is associated with coronary artery disease in Han Chinese: Relation with endothelial ADMA levels.

[PMID 20518787] Comparison between self-reported facial flushing after alcohol consumption and ALDH2 Glu504Lys polymorphism for risk of upper aerodigestive tract cancer in a Japanese population.

[PMID 20616999OA-icon.png] Usefulness of Mendelian randomization in observational epidemiology.

[PMID 21351086OA-icon.png] Shortened telomeres in individuals with abuse in alcohol consumption.

[PMID 21437268OA-icon.png] A genome-wide association study of upper aerodigestive tract cancers conducted within the INHANCE consortium.

[PMID 21455501OA-icon.png] Genetic variants on chromosome 8q24 and colorectal neoplasia risk: a case-control study in China and a meta-analysis of the published literature.

[PMID 21576033] ADH1B and ALDH2 polymorphisms and their associations with increased risk of squamous cell carcinoma of the head and neck in the Korean population.

[PMID 21900886OA-icon.png] Pharmacogenetics of naltrexone in asian americans: a randomized placebo-controlled laboratory study.

[PMID 21917409] Alcohol drinking, mean corpuscular volume of erythrocytes, and alcohol metabolic genotypes in drunk drivers.

[PMID 21946912] Folate, alcohol, and aldehyde dehydrogenase 2 polymorphism and the risk of oral and pharyngeal cancer in Japanese.

[PMID 22004425] Genetic risk of hepatocellular carcinoma in patients with hepatitis C virus: a case control study.

[PMID 23060937OA-icon.png] A variant allele of ADH1B and ALDH2, is associated with the risk of esophageal cancer

GET Evidence
aa_change Glu504Lys
aa_change_short E504K
impact pathogenic
qualified_impact Insufficiently evaluated pathogenic
overall_frequency 0.0104167

Alcohol Consumption, Smoking and Risk of Esophageal Cancer

GWAS snp
PMID [PMID 22797727]
Trait Renal function-related traits (sCR)
Title Meta-analysis identifies multiple loci associated with kidney function-related traits in east Asian populations.
Risk Allele A
P-val 3E-10
Odds Ratio .00 [0.0031-0.0059] mg/dl increase

[PMID 23685282] Association of genetic polymorphisms in ADH and ALDH2 with risk of coronary artery disease and myocardial infarction: A meta-analysis

[PMID 23697560] ALDH2 rs671 Polymorphism and Coronary Heart Disease Risk Among Asian Populations: A Meta-Analysis and Meta-Regression

[PMID 23430454] Genetic variants at 4q21, 4q23 and 12q24 are associated with esophageal squamous cell carcinoma risk in a Chinese population

[PMID 24277619OA-icon.png] Associated to alcohol dependence and is the major genetic determinant of "daily maximum drinks" in a GWAS study of an isolated rural Chinese sample

[PMID 22560290] A comparison of Val81Met and other polymorphisms of alcohol metabolising genes in patients and controls in Northern Spain.

[PMID 22930414OA-icon.png] Single nucleotide polymorphisms of ADH1B, ADH1C and ALDH2 genes and esophageal cancer: a population-based case-control study in China.

[PMID 23088731] Tag single nucleotide polymorphisms of alcohol-metabolizing enzymes modify the risk of upper aerodigestive tract cancers: HapMap database analysis.

[PMID 23243119] Is aldehyde dehydrogenase 2 a credible genetic instrument for alcohol use in Mendelian randomization analysis in Southern Chinese men?

[PMID 23364009] Common variants at 12q24 are associated with drinking behavior in Han Chinese.

[PMID 23455379] The aldehyde dehydrogenase 2 (ALDH2) Glu504Lys polymorphism interacts with alcohol drinking in the risk of stomach cancer.

[PMID 25427900] Genetic-Epidemiological Evidence for the Role of Acetaldehyde in Cancers Related to Alcohol Drinking

GWAS snp
PMID [PMID 24861553OA-icon.png]
Trait Body mass index
Title Meta-analysis of genome-wide association studies in East Asian-ancestry populations identifies four new loci for body mass index.
Risk Allele G
P-val 3E-11
Odds Ratio .04 [0.027-0.049] unit increase

[PMID 25680115OA-icon.png] Association between Glu504Lys Polymorphism of ALDH2 Gene and Cancer Risk: A Meta-Analysis

[PMID 25848305OA-icon.png] Clinical significance of ALDH2 rs671 polymorphism in esophageal cancer: evidence from 31 case-control studies

[PMID 25102261] Maternal folate, alcohol and energy metabolism-related gene polymorphisms and the risk of recurrent pregnancy loss

[PMID 25524923] Genetic polymorphisms of ADH1B, ADH1C and ALDH2, alcohol consumption, and the risk of gastric cancer: the Japan Public Health Center-based prospective study

[PMID 25636114] [Advance in research on the association of ALDH2 gene polymorphisms with cancer susceptibility in drinkers]

[PMID 26842247] Association Study of Gene Polymorphisms in GABA, Serotonin, Dopamine, and Alcohol Metabolism Pathways with Alcohol Dependence in Taiwanese Han Men.