title: Epi2Loc: an R package to investigate two-locus epistatic models.
abstract: Epistasis is a growing area of research in genome-wide studies, but the differences between alternative definitions of epistasis remain a source of confusion for many researchers. One problem is that models for epistasis are presented in a number of formats, some of which have difficult-to-interpret parameters. In addition, the relation between the different models is rarely explained. Existing software for testing epistatic interactions between single-nucleotide polymorphisms (SNPs) does not provide the flexibility to compare the available model parameterizations. For that reason we have developed an R package for investigating epistatic and penetrance models, Epi2Loc, to aid users who wish to easily compare, interpret, and utilize models for two-locus epistatic interactions. Epi2Loc facilitates research on SNP-SNP interactions by allowing the R user to easily convert between common parametric forms for two-locus interactions, generate data for simulation studies, and perform power analyses for the selected model with a continuous or dichotomous phenotype. The usefulness of the package for model interpretation and power analysis is illustrated using data on rheumatoid arthritis.
authors.affiliation: Department of Psychology,University of Notre Dame,Notre Dame,IN,USA.
authors.forename: Raymond K
authors.initials: RK
authors.lastname: Walters
authors.affiliation: Department of Psychology,University of Notre Dame,Notre Dame,IN,USA.
authors.forename: Charles
authors.initials: C
authors.lastname: Laurin
authors.affiliation: Department of Psychology,University of Notre Dame,Notre Dame,IN,USA.
authors.forename: Gitta H
authors.initials: GH
authors.lastname: Lubke
mesh_terms: D001172:Arthritis, Rheumatoid / Q000235:genetics*; D004843:Epistasis, Genetic; D006801:Humans; D008957:Models, Genetic; D019683:Penetrance; D020641:Polymorphism, Single Nucleotide; D012984:Software