DS.gamma {BayesQTLBIC} | R Documentation |
Calculate Darvasi and Soller correction factor gamma for QTL mapping in selectively genotyped populations
DS.gamma(p)
p |
proportion sampled (p/2 per sampled tail) |
For a given number of individuals genotyped, power of detection of QTL for a continuous trait (assumed normally distributed) is increased if individuals are sampled from the tails of the phenotypic distribution. For small gene effects, if proportion p/2 is sampled from each tail of the phenotypic distribution, naive estimates of marker effects are inflated by the factor gamma_p (to first order in the size of gene effects) where:
gamma_p = 1 + qnorm((1 - p/2)*dnorm(qnorm(p/2))/(p/2))
the value of gamma_p
Rod Ball (rod.ball@AT@scionresearch.com)
Darvasi, A. and Soller, M. 1992: Selective genotyping for determination of linkage between a locus and a quantitative trait locus. Theoretical and Applied Genetics 85: 353–359.
DS.gamma(p = c(0.05,0.1,0.25))