title: A genetic analysis of smoking behavior in family members of older adult males.
abstract: OBJECTIVE
  To conduct a genetic study of smoking behavior in 493 three-generation families.
  
  
  METHODS
  Complex segregation analysis and maximum likelihood statistics were used to describe the familial clustering of ever-smoking under several transmission models.
  
  
  METHODS
  The Western Collaborative Group Study, an ageing and health study currently in its 39th year of follow-up.
  
  
  METHODS
  Probands were male participants who were of mean age 71.6 years at the time of the family history interview in 1986-88.
  
  
  METHODS
  Data were collected via an interview that focused on the family smoking history of participants. Smoking histories of all first-degree relatives were obtained from probands.
  
  
  RESULTS
  Evidence for genetic transmission was indicated by rejection of both the environmental and sporadic models in favor of a Mendelian genetic model with residual familial effects from spouses and both parents.
  
  
  CONCLUSIONS
  The best-fitting model was that of a dominant major gene with low estimated frequency and residual familial correlations. This is the first study to date to model the familial transmission of ever-smoking in three-generation families.
authors.affiliation: Center for Health Sciences, SRI International, Menlo Park, CA 94025-3493, USA.
authors.forename: L S
authors.initials: LS
authors.lastname: Cheng
authors.forename: G E
authors.initials: GE
authors.lastname: Swan
authors.forename: D
authors.initials: D
authors.lastname: Carmelli
mesh_terms: D000368:Aged; D020090:Chromosome Segregation; D005192:Family Health; D005799:Genes, Dominant / Q000235:genetics*; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006801:Humans; D008297:Male; D008957:Models, Genetic; D012737:Sex Factors; D014029:Tobacco Use Disorder / Q000235:genetics*; D014481:United States