title: Tests for candidate-gene interaction for longitudinal quantitative traits measured in a large cohort.
abstract: For the Framingham Heart Study (FHS) and simulated FHS (FHSsim) data, we tested for gene-gene interaction in quantitative traits employing a longitudinal nonparametric association test (LNPT) and, for comparison, a survival analysis. We report results for the Offspring Cohort by LNPT analysis and on all longitudinal cohorts by survival analysis with cohort effect adjustment. We verified that type I errors were not inflated. We compared the power of both methods to detect in FHSsim data two sets of gene pairs that interact for the trait coronary artery calcification. In FHS, we tested eight gene pairs from a list of candidate genes for interaction effects on body mass index. Both methods found evidence for pairwise non-additive effects of mutations in the genes FTO, PON1, and PFKP on body mass index.
authors.affiliation: Department of Genetic Epidemiology, University Medical Center, University of Goettingen, Humboldtallee 32, D-37073 Goettingen, Germany. dmalzah@gwdg.de.
authors.forename: Dörthe
authors.initials: D
authors.lastname: Malzahn
authors.forename: Yesilda
authors.initials: Y
authors.lastname: Balavarca
authors.forename: Jingky P
authors.initials: JP
authors.lastname: Lozano
authors.forename: Heike
authors.initials: H
authors.lastname: Bickeböller