title: ADH and ALDH polymorphisms and alcohol dependence in Mexican and Native Americans.
abstract: BACKGROUND
  Ethanol is primarily metabolized in the liver by two rate-limiting reactions: conversion of ethanol to acetaldehyde by alcohol dehydrogenase (ADH) and subsequent conversion of acetaldehyde to acetate by aldehyde dehydrogenase (ALDH). ADH and ALDH exist in multiple isozymes that differ in their kinetic properties. Notably, polymorphisms within the genes that encode for these isozymes vary in their allele frequencies between ethnic groups, and thus, they have been considered as candidate genes that may differentially influence risk for the development of alcohol dependence across ethnic groups.
  
  
  OBJECTIVE
  Associations between alcohol dependence and polymorphisms in ADH1B, ADH1C, and ALDH2 were compared in a community sample of Native Americans (n 791) living on reservations and Mexican Americans (n 391) living within the same county.
  
  
  RESULTS
  Two Mexican Americans and no Native Americans possessed one ALDH2*2 allele. Presence of at least one ADH1B*2 allele was found in 7% of the Native Americans and 13% of the Mexican Americans, but was only associated with protection against alcohol dependence in the Mexican Americans. Presence of at least one ADH1B*3 allele was found in 4% of the Native Americans and 2% of the Mexican Americans, but was associated with protection against alcohol dependence only in the Native Americans. No associations between alcohol dependence and polymorphisms in ADH1C were found.
  
  
  CONCLUSIONS
  Polymorphisms in ADH1B are protective against alcoholism in these two populations; however, these findings do not explain the high prevalence of alcoholism in these populations.
authors.affiliation: Department of Molecular and Integrative Neurosciences, The Scripps Research Institute , La Jolla, CA 92037, USA. cindye@scripps.edu
authors.forename: Cindy L
authors.initials: CL
authors.lastname: Ehlers
authors.forename: Tiebing
authors.initials: T
authors.lastname: Liang
authors.forename: Ian R
authors.initials: IR
authors.lastname: Gizer
mesh_terms: D000079:Acetaldehyde / Q000378:metabolism; D000328:Adult; D000426:Alcohol Dehydrogenase / Q000235:genetics*; D000437:Alcoholism / Q000453:epidemiology / Q000235:genetics*; D000444:Aldehyde Dehydrogenase / Q000235:genetics*; D000071396:Aldehyde Dehydrogenase, Mitochondrial; D000483:Alleles; D000431:Ethanol / Q000378:metabolism*; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D007198:Indians, North American / Q000235:genetics; D008297:Male; D017058:Mexican Americans / Q000235:genetics; D011110:Polymorphism, Genetic; D015995:Prevalence; D055815:Young Adult
chemical_list: D000431:Ethanol; C489332:ADH1B protein, human; C420272:ADH1C protein, human; D000426:Alcohol Dehydrogenase; C096127:ALDH2 protein, human; D000444:Aldehyde Dehydrogenase; D000071396:Aldehyde Dehydrogenase, Mitochondrial; D000079:Acetaldehyde