title: A genome-wide linkage and association study using COGA data.
abstract: BACKGROUND
  Genome-wide association will soon be available to use as an adjunct to traditional linkage analysis. We studied alcoholism in 119 families collected by the Collaborative Study on the Genetics of Alcoholism and made available in Genetic Analysis Workshop 14, using genome-wide linkage and association analyses.
  
  
  METHODS
  Genome-wide linkage analysis was first performed using microsatellite markers and a region with the strongest linkage evidence was further analyzed using single-nucleotide polymorphisms (SNPs). Family based genome-wide association test was also conducted using the SNPs.
  
  
  RESULTS
  Nonparametric linkage analysis revealed weak linkage evidence on chromosome 7, and association analysis identified SNP tsc0515272 on chromosome 3 as significantly associated with alcoholism.
  
  
  CONCLUSIONS
  Linkage analysis may require large sample sizes and high quality genotyping and marker maps to adequately improve power, while association analysis could hold more promise in efforts to identify variants responsible for complex traits.
authors.affiliation: Department of Preventive Medicine and Epidemiology, Loyola University Medical Center, Maywood, IL 60153, USA. xzhu1@lumc.edu
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Zhu
authors.forename: Richard
authors.initials: R
authors.lastname: Cooper
authors.forename: Donghui
authors.initials: D
authors.lastname: Kan
authors.forename: Guichan
authors.initials: G
authors.lastname: Cao
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Wu
mesh_terms: D000437:Alcoholism / Q000453:epidemiology / Q000235:genetics*; D003299:Cooperative Behavior; D030541:Databases, Genetic; D005190:Family; D008040:Genetic Linkage; D055106:Genome-Wide Association Study; D006801:Humans; D008126:Lod Score; D018895:Microsatellite Repeats / Q000235:genetics; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D018709:Statistics, Nonparametric