Rs1229984

A SNP in rs1229984 encodes a form of the alcohol dehydrogenase ADH1B gene that significantly reduces the clearance rate of alcohol from the liver. This SNP is also known as Arg48His, with the (G) allele corresponding to the Arg and the (A) to the His.

Known in the literature as ADH2*2 or sometimes ADH1B*2, the allele with increased activity (meaning more rapid oxidation of ethanol to acetaldehyde) is His48, encoded by rs1229984(A). Individuals with one or especially two ADH2*2 alleles, ie genotypes rs1229984(A;G) or rs1229984(A;A) are more likely to find drinking unpleasant and have a somewhat reduced risk for alcoholism.

A study of over 3,800 cases of "upper aerodigestive" cancers (mouth/throat, voice box, and esophageal cancers) concluded that the rs1229984(A) allele (in dbSNP orientation) has a protective effect. Carriers of this allele had a 0.56x (decreased; p=10-10) risk of having one of these cancer types.

A review of the (at times conflicting) findings regarding ADH1B genotypes and maternal and fetal alcohol syndromes is available.

A study of 4,500+ Australian twins concluded that rs1229984(G) carriers flush less after alcohol consumption, consumed alcohol on more occasions, had a higher maximum number of alcoholic drinks in a single day and had a higher overall alcohol consumption in the previous year than those with the less common (A) allele.

The rs1229984(A;G) genotype might be associated with a decreased risk for migraine, and the rs1229984(A) allele may be related with the risk for triggering migraine attacks after alcohol consumption based on a study of 197 Spanish patients.

Note: this is not the SNP associated with the "Asian Blush" (rs671), although there are several studies looking at individuals with varying combinations of SNPs rs671 and rs1229984.

According to a 23andMe discussion This is one of the SNPs which were re-analyzed April 2009. Customers with older data may wish to redownload. SNPs effected rs4420638, rs34276300, rs3091244, rs34601266, rs2033003, rs7900194, rs9332239, rs28371685, rs1229984, and rs28399504.

A global perspective on genetic variation at the ADH genes reveals unusual patterns of linkage disequilibrium and diversity.

A haplotype map of the human genome.

Diplotype trend regression analysis of the ADH gene cluster and the ALDH2 gene: multiple significant associations with alcohol dependence.

Multiple ADH genes modulate risk for drug dependence in both African- and European-Americans.

Evidence of positive selection on a class I ADH locus.

Association of ADH and ALDH genes with alcohol dependence in the Irish Affected Sib Pair Study of alcohol dependence (IASPSAD) sample.

Ethnic related selection for an ADH Class I variant within East Asia.

Genetic susceptibility to heroin addiction: a candidate gene association study.

Prevalence in the United States of selected candidate gene variants: Third National Health and Nutrition Examination Survey, 1991-1994.

ADH single nucleotide polymorphism associations with alcohol metabolism in vivo.

Gene-environmental interaction regarding alcohol-metabolizing enzymes in the Japanese general population.

ADH1A variation predisposes to personality traits and substance dependence.

Population differentiation as an indicator of recent positive selection in humans: an empirical evaluation.

The ADH1B Arg47His polymorphism in east Asian populations and expansion of rice domestication in history.

ADH1B*2 allele is protective against alcoholism but not chronic liver disease in the Hungarian population.

The association of alcohol and alcohol metabolizing gene variants with diabetes and coronary heart disease risk factors in a white population.

Alcohol-metabolizing enzyme gene polymorphisms in the Basque Country, Morocco, and Ecuador.

Shortened telomeres in individuals with abuse in alcohol consumption.

Alcohol-dehydrogenase (ADH1B) Arg48His polymorphism in Basque Country patients with oral and laryngeal cancer: preliminary study.

Strong association of the alcohol dehydrogenase 1B gene (ADH1B) with alcohol dependence and alcohol-induced medical diseases.

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

Alcohol dehydrogenase-1B Arg47His polymorphism and upper aerodigestive tract cancer risk: a meta-analysis including 24,252 subjects.

Pharmacogenetics of naltrexone in asian americans: a randomized placebo-controlled laboratory study.

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

Population-specific genetic associations with oesophageal squamous cell carcinoma in South Africa.

ADH1B is associated with alcohol dependence and alcohol consumption in populations of European and African ancestry.

ADH1B polymorphism, alcohol consumption, and binge drinking in Slavic Caucasians: results from the Czech HAPIEE study.

Determination of the effects of alcohol dehydrogenase (ADH) 1B and ADH1C polymorphisms on alcohol dependence in Turkey.