Linkage Analysis Flashcards
Linkage
the tendency of closely positioned DNA segments or genes to be segregated/inherited together
The use of DNA markers near or within a gene to track a disease-causing mutation within a family.
Linkage analysis
DNA segments with enough variation between individuals (SNP, RFLP, VNTR) that their inheritance/co-inheritance with alleles can traced through a family.
Markers
Phase
The alleles of 2/more closely linked markers–“haplotype”that passes from parent to child
T/F: Linkage analysis is best carried out using very distant markers/
F: tightly linked markers
Recombination yields a new:
haplotype
Linkage disequilibrium
In a population, alleles occur together more frequently than would be predicted by random chance
What causes over-representation of specific haplotypes?
Linkage disequilibrium–they’re so tightly linked, recombination is unlikely
Genetic testing to identify closely linked DNA
haplotype analysis (used when a given trait is in linkage disequilibrium with a set of markers)
If there are many hotspots between genes, how likely is linkage disequilibrium?
Not…
What does direct testing analyze?
Known disease allele
What does indirect testing analyze?
Unknown disease allele, using multiple closely linked markers
Linkag analysis is (direct/indirect)
Indirect
What limits linkage analysis?
The chance of recombination
