title: An evaluation of the variance components approach: type I error, power and size of the estimated effect.
abstract: In order to evaluate the statistical properties of the variance components method implemented in SOLAR and GENEHUNTER2, the type I error rate, power and estimated size of modelled effects were determined using computer simulation. Results suggested that the type I error rate was quite conservative when the variance was completely due to random effects. However, when either a polygenic effect or an unlinked single locus component effect was included in the generating models the type I error rate was closer to the nominal level. The size of the polygenic or single locus effect appeared to influence the type I error rate. Results suggested that the variance components method underestimated the variance attributed to a single locus effect and overestimated the variance attributed to a polygenic effect in the models considered regardless of the source of variation.
authors.affiliation: Department of Epidemiology, School of Public Health, Johns Hopkins University, Baltimore, MD, USA. yyao@jhsph.edu
authors.forename: Yin Yao
authors.initials: YY
authors.lastname: Shugart
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: O'Connell
authors.forename: Alexander F
authors.initials: AF
authors.lastname: Wilson
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002874:Chromosome Mapping / Q000706:statistics & numerical data*; D005819:Genetic Markers; D006801:Humans; D008126:Lod Score; D008957:Models, Genetic
chemical_list: D005819:Genetic Markers