Rs671

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 6582480]

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]

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

spittoon carriers of the A allele are prone to esophageal cancer, which is also known as upper aerodigestive tract (UAT) cancer.

[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 19641380] 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 22102315] 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]
Trait
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 21971053]
Trait
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]
Trait
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