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An extension of, and comments on,
Example 13.
Recent references on marker-assisted introgressions (pages 407--413)
Background: While the TDT is presented in the book (pages 420-422) as an approach for
detecting linkage of a major QTL to a very tightly-linked marker that controls for the
effects of population stratification (see Example 17, Chapter 14), it is now appreciated that it often has more power than allele-sharing methods (such as ASP, etc., see Chapter 16, pp. 525- 533) for detecting linkage to tightly-linked markers.
Background: Suppose a number of independent studies have been performed to
test for linkage. How can one combine the data from all these tests into a single analysis, especially if the experimental designs are quite different in the different experiments?
The statistical field of meta-analysis discusses how to obtain an overall p value given the p values m independent tests. Specifically, let p(i) be the p-value for the i-th test. With m independent tests, -2 Sum Ln[p(i)] follows a chi-square distribution with 2m df (Fisher 1954, pg. 99, Statistical Methods for Research Workers, 12th ed). Recent papers using meta-analysis on linkage data are:
Identifying And Incorporating Genetic Markers And Major Genes In Animal
Breeding Programs by Brian Kinghorn and Julius van der Werf (pdf file). Notes from a course given in Belo Horizonte (Brazil)
31 May to 5 June 2000.
The Journal of Quantitative Trait Loci (JQTL),, an electronic journal sponsored by the Crop Science Society of America
Home Pages:
[ Volume One ] -
[ Volume Two ] - [ What's new ] -
[ Book]
Bruce Walsh. jbwalsh@u.arizona.edu .
Comments welcome.
The Transmission/Disequilibrium Test (TDT)
(Posted 30 Jan 1998) Meta-analysis of linkage data
(Posted 23 April 1998)
Workshop notes
Journals
WWW pages of interest
QTL meetings
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Created 25 February 1995, last updated 11 April 2001