title: Bioinformatics tools enabling u-statistics for microarrays.
abstract: It is rare that a single gene is sufficient to represent all aspects of genomic activity. Similarly, most common diseases cannot be explained by a mutations at a single locus. Since complex systems tend to be neither linear nor hierarchical in nature, but to have correlated components of unknown relative importance, the assumptions of traditional (parametric) multivariate statistical methods can rarely be justified on theoretical grounds. Empirical "validation" is not only problematic, but also time consuming. Here we demonstrates how bioinformatics tools, ranging from spreadsheets to grids, can enable u-statistics as a non-parametric alternative for scoring multivariate ordinal data. Applications are shown to improve assessment of genetic risk factors, quality control of microarrays and signal value estimation, scoring genomic profiles that best correlated with complex risk factors (cardiovascular diseases), and complex responses to an intervention (treatment of psoriasis).
authors.affiliation: Gen. Clinical Res. Center, Rockefeller Univ. Hosp., New York, NY 10021, kmw@rockefeller.edu .
authors.forename: Knut M
authors.initials: KM
authors.lastname: Wittkowski
authors.forename: Asifa
authors.initials: A
authors.lastname: Haider
authors.forename: Ephraim
authors.initials: E
authors.lastname: Sehayek
authors.forename: Mayte
authors.initials: M
authors.lastname: Suárez-Fariñas
authors.forename: Maurizio
authors.initials: M
authors.lastname: Pellegrino
authors.forename: Alexandre
authors.initials: A
authors.lastname: Peshansky
authors.forename: Cameron
authors.initials: C
authors.lastname: Coffran
authors.forename: Sanford
authors.initials: S
authors.lastname: Coker
mesh_terms: D001698:Biomedical Engineering; D002318:Cardiovascular Diseases / Q000235:genetics; D019295:Computational Biology; D005260:Female; D020869:Gene Expression Profiling / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D046228:Microarray Analysis / Q000592:standards / Q000706:statistics & numerical data*; D015233:Models, Statistical; D011565:Psoriasis / Q000473:pathology; D011786:Quality Control; D012307:Risk Factors; D018709:Statistics, Nonparametric