18. Clustering on a Tree
Complete penetrance
Incomplete penetrance
Spurious disease
19. Clustering on a Tree
25%
Case/control clustering
is not random on the tree...
75%
40%
60%
20. Using âPerfect Phylogeniesâ
Use the four-gamete test to ïŹnd regions that
can be explained by a tree with no recurrent mutations
Mailund, Besenbacher & Schierup 2006
25. Scoring the Clustering
Red=cases
Green=controls
Are the case chromosomes signiïŹcantly
over-represented in some clusters?
26.
27. Wild-types
Mutation
Mutants
We can place âmutationsâ on the tree edges
and partition chromosomes into âmutantsâ
and âwild-typesâ and test for different
distributions of cases and controls
28. Wild-types
Mutation
Mutants
Use average or maximum to score the tree
Average is kosher Bayesian stats; maximum
needs to be corrected for over-ïŹtting.