title: Potential for gene-gene confounding bias in case-parental control studies.
abstract: OBJECTIVE
  To show the potential for gene-gene confounding bias in case-parental control studies.
  
  
  METHODS
  The authors quantify the magnitude of gene-gene confounding bias using simple mathematical equations. They also demonstrate the potential problems of such a bias with hypothetical (but realistic) examples.
  
  
  RESULTS
  The degree of bias resulting from gene-gene confounding was found to be quite substantial under certain conditions (two genes are very closely linked and/or the study was performed in a recently admixed population).
  
  
  CONCLUSIONS
  In this post-genomic era more and more encounters of the gene-gene confounding will be expected, if the one-gene-at-a-time approach continues to be adopted.
authors.affiliation: Graduate Institute of Epidemiology, College of Public Health, National Taiwan University, Taiwan, Republic of China. wenchung@ha.mc.ntu.edu.tw
authors.forename: Wen-Chung
authors.initials: WC
authors.lastname: Lee
authors.forename: Yen-Yi
authors.initials: YY
authors.lastname: Ho
mesh_terms: D015982:Bias; D015986:Confounding Factors, Epidemiologic; D004812:Epidemiologic Methods; D020022:Genetic Predisposition to Disease / Q000453:epidemiology*; D006801:Humans; D017720:Molecular Epidemiology