Lecture 16 - Linkage and Association Studies Flashcards
What are the two major FACTORS important for gene mapping?
- Penetrance
2. Inheritance patterns
For alleles to be inherited together, they must be:
close together on a chromosome
What are the two major METHODS of gene mapping?
- Linkage method
2. Association method
The ________ method of gene mapping tracks the inheritance of large chromosomal regions with a disease in a family.
linkage method
The _______ method of gene mapping uses markers to identify chromosomal regions.
linkage method
The ________ method of gene mapping tracks the coinheritance of small chromosomal regions (markers) between cases and controls - population based study.
association method
The relationship between a phenotype and a genotype is called:
penetrance
A lod score of +3 would be considered a threshold for;
establishing linkage
A lod score of -2 is considered as the threshold:
against linkage
If loci A and B are on different chromosomes then they are in ________ ad independent assortment will always hold.
repulsion
If loci A and B are on the same chromosome, they are in _______ and they can still assort independently depending on how far apart they are on the chromosome.
coupling (syntenic)
Why can syntenic loci show independent assortment?
Homologous chromosomes exhibit crossing over
When are genetic markers most useful (informative)?
When it is highly polymorphic
Robert has Marfan syndrome and exhibits ectopic lenti, arachnodactyly, scoliosis and aortic dissection. His brother Bob also has Marfan syndrome and only exhibits joint hypermobility. This is an example of:
A. Variable Penetrance
B. Variable expression
C. Allelic heterogeneity
D. Locus heterogeneity
B.
