![[Back]](/images/prevpage.gif)
![[Index]](/images/index.gif)
![[Help]](/images/help.gif)
![[MSI]](/images/msi.gif)
![[ANU Online]](/images/online.gif)
Research Report SRR00-005
Evaluating linkage and linkage disequilibrium: Use of excess sharing and transmission disequilibrium methods in affected sib pairs
J. Wicks and S.R. Wilson
Abstract:
Two popular and robust approaches to analysing affected
sib pair (ASP) data for linkage are the traditional excess sharing
methods and the transmission/disequilibrium test (TDT). Here we
derive an overall test of linkage for multi-allelic ASP marker
data which comprises two component tests: one for excess sharing
and one for transmission disequilibrium. This method has several
advantages. Firstly the overall test of linkage is often more
powerful than either of the two component tests. Secondly the
method makes it is possible to determine the contribution of
linkage disequilibrium (LD), in addition to linkage, to an overall
positive linkage result. This is useful because the presence of
LD in addition to linkage may suggest that the marker locus is in
very close proximity to a disease susceptibility gene. Thirdly
the method provides estimates of the risk associated with
transmission of the different marker alleles.
This service is maintained by the
Mathematical Sciences Institute (MSI)
Comments to
webmaster@maths.anu.edu.au
URL: http://wwwmaths.anu.edu.au/