Identifying/Finding Disease Genes

Question 1

1 Map Unit =

Answer 1

1 cM
1% recombination frxn
approx 1 million bases

Question 2

What is Phase all about

Answer 2

Determining whether the alternative alleles for two loci are in the same or different chromosomes (Coupling = the same. Repulsion = Opposites)

Question 3

Generic explanation of genetic mapping studies

Answer 3

Testing markers on different chromosomes looking for evidence of linkage to the disease. Typically need multiple affected family members for this approach. The marker is NOT the same as the diseased gene.

Question 4

How to interpret a LOD score

Answer 4

(Likelihood of linkage)/(likelihood of no linkage)
Over 3 = Good Evidence of Linkage
Over 1 = Positive
Under 1 = Negative

Question 5

Potential Error seen in a diagnostic linkage study =

Answer 5

distancein cM between the two genes

Question 6

Homozygosity mapping is really helpef if a study is done with…

Answer 6

Incest families

Question 7

Association studies assess…

Answer 7

Presence of a particular marker or allele found either significantly more frequently or significantly less frequently in a group of affected individuals

Question 8

Why might associations be in place?

Answer 8

Susceptability Allele
Founder Effect
Closely Linked
Relatively recent mutation

Question 9

In order to conclude non-paternity, you need…

Answer 9

exclusion with at least different markers