title: ZODET: software for the identification, analysis and visualisation of outlier genes in microarray expression data.
abstract: CONCLUSIONS
  Complex human diseases can show significant heterogeneity between patients with the same phenotypic disorder. An outlier detection strategy was developed to identify variants at the level of gene transcription that are of potential biological and phenotypic importance. Here we describe a graphical software package (z-score outlier detection (ZODET)) that enables identification and visualisation of gross abnormalities in gene expression (outliers) in individuals, using whole genome microarray data. Mean and standard deviation of expression in a healthy control cohort is used to detect both over and under-expressed probes in individual test subjects. We compared the potential of ZODET to detect outlier genes in gene expression datasets with a previously described statistical method, gene tissue index (GTI), using a simulated expression dataset and a publicly available monocyte-derived macrophage microarray dataset. Taken together, these results support ZODET as a novel approach to identify outlier genes of potential pathogenic relevance in complex human diseases. The algorithm is implemented using R packages and Java.
  
  
  BACKGROUND
  The software is freely available from http://www.ucl.ac.uk/medicine/molecular-medicine/publications/microarray-outlier-analysis.
authors.affiliation: Division of Medicine, University College London, London, United Kingdom.
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Roden
authors.affiliation: Division of Medicine, University College London, London, United Kingdom.
authors.forename: Gavin W
authors.initials: GW
authors.lastname: Sewell
authors.affiliation: Division of Medicine, University College London, London, United Kingdom.
authors.forename: Anna
authors.initials: A
authors.lastname: Lobley
authors.affiliation: Division of Medicine, University College London, London, United Kingdom.
authors.forename: Adam P
authors.initials: AP
authors.lastname: Levine
authors.affiliation: Division of Medicine, University College London, London, United Kingdom.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Smith
authors.affiliation: Division of Medicine, University College London, London, United Kingdom.
authors.forename: Anthony W
authors.initials: AW
authors.lastname: Segal
mesh_terms: D001483:Base Sequence; D005786:Gene Expression Regulation; D005796:Genes; D006801:Humans; D008264:Macrophages / Q000378:metabolism; D008969:Molecular Sequence Data; D009000:Monocytes / Q000166:cytology; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D012372:ROC Curve; D015203:Reproducibility of Results; D012984:Software; D014584:User-Computer Interface