title: Volume measures for linkage disequilibrium.
abstract: BACKGROUND
  Defining measures of linkage disequilibrium (LD) that have good small sample properties and are applicable to multiallelic markers poses some challenges. The potential of volume measures in this context has been noted before, but their use has been hampered by computational challenges.
  
  
  RESULTS
  We design a sequential importance sampling algorithm to evaluate volume measures on I x J tables. The algorithm is implemented in a C routine as a complement to exhaustive enumeration. We make the C code available as open source. We achieve fast and accurate evaluation of volume measures in two dimensional tables.
  
  
  CONCLUSIONS
  Applying our code to simulated and real datasets reinforces the belief that volume measures are a very useful tool for LD evaluation: they are not inflated in small samples, their definition encompasses multiallelic markers, and they can be computed with appreciable speed.
authors.affiliation: Department of Statistics, University of Illinois at Urbana-Champaign, Champaign IL 61820, USA. yuguo@uiuc.edu <yuguo@uiuc.edu>
authors.forename: Yuguo
authors.initials: Y
authors.lastname: Chen
authors.forename: Chia-Ho
authors.initials: CH
authors.lastname: Lin
authors.forename: Chiara
authors.initials: C
authors.lastname: Sabatti
mesh_terms: D000465:Algorithms; D000483:Alleles; D002874:Chromosome Mapping; D002892:Chromosomes, Human, Pair 22; D003198:Computer Simulation; D005819:Genetic Markers; D005828:Genetics, Population; D006801:Humans; D015810:Linkage Disequilibrium; D018401:Sample Size
chemical_list: D005819:Genetic Markers