title: Biometrical genetic analysis of the cotwin control design.
abstract: The twin-cotwin matched case-control design can be interpreted in terms of bivariate genetic factor models. I derive expressions for the expected intrapair difference for a trait correlated with the variable on which discordance was selected.
authors.affiliation: Epidemiology Unit, Queensland Institute of Medical Research, Brisbane, Australia.
authors.forename: D L
authors.initials: DL
authors.lastname: Duffy
mesh_terms: D000704:Analysis of Variance; D016022:Case-Control Studies; D005163:Factor Analysis, Statistical; D006801:Humans; D008957:Models, Genetic; D010641:Phenotype; D018433:Twin Studies as Topic / Q000706:statistics & numerical data*; D014427:Twins / Q000235:genetics*