title: lodGWAS: a software package for genome-wide association analysis of biomarkers with a limit of detection.
abstract: Genome-wide association study (GWAS) of a biomarker is complicated when the assay procedure of the biomarker is restricted by a Limit of Detection (LOD). Those observations falling outside the LOD cannot be simply discarded, but should be included into the analysis by applying an appropriate statistical method. However, the problem of LOD in GWAS analysis of such biomarkers is usually overlooked. 'lodGWAS' is a flexible, easy-to-use R package that provides a simple and elegant way for GWAS analysis of such biomarkers while simultaneously accommodating the problem of LOD by applying a parametric survival analysis method.
  
  
  
  http://cran.r-project.org/web/packages/lodGWAS CONTACTS: a.vaez@umcg.nl or i.m.nolte@umcg.nl
  
  
  
  Supplementary data are available at Bioinformatics online.
authors.affiliation: Department of Epidemiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran and.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Vaez
authors.affiliation: Department of Epidemiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: van der Most
authors.affiliation: Department of Epidemiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Bram P
authors.initials: BP
authors.lastname: Prins
authors.affiliation: Department of Epidemiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Harold
authors.initials: H
authors.lastname: Snieder
authors.affiliation: Department of Epidemiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands, Department of Mathematics and Computer Science, Eindhoven University of Technology, Eindhoven, The Netherlands.
authors.forename: Edwin
authors.initials: E
authors.lastname: van den Heuvel
authors.affiliation: Department of Epidemiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Behrooz Z
authors.initials: BZ
authors.lastname: Alizadeh
authors.affiliation: Department of Epidemiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Ilja M
authors.initials: IM
authors.lastname: Nolte
mesh_terms: D015415:Biomarkers; D055106:Genome-Wide Association Study / Q000379:methods*; D006801:Humans; D057230:Limit of Detection; D012984:Software
chemical_list: D015415:Biomarkers