Lecture 2: Genetic Analysis in Humans

Question 1

What are problems of genetic analysis in humans?

Answer 1

Cannot do controlled mating 
Few progeny 
Long generational time
Few useful single gene variants 
Analysis based on pedigree

Question 2

Name 4 different types of genetic disorders

Answer 2

Single gene disorder
Chromosomal disorder
Multifactorial
Mitochondrial

Question 3

Is mitochondrial inheritance maternal or paternal?

Answer 3

Maternal

Question 4

Define penetrance

Answer 4

The proportion of people with the relevant genotype who show the character

Question 5

Define expressivity

Answer 5

The degree at which an individual with the relevant genotype displays the characteristics of a condition

Question 6

Give an example of a disease with variable expressivity

Answer 6

Neurofibromatosis

Question 7

What does a pedigree analysis tell us?

Answer 7

Mode of inheritance

Question 8

What is a LOD score?

Answer 8

Measure of probability of linkage between gene and marker at given recombination frequency

Question 9

What does a LOD score of above 3 mean?

Answer 9

Likely to be linked

Question 10

What does a LOD score of less than -2 mean

Answer 10

Unlikely to be linked

Question 11

What is a haplotype

Answer 11

Set of alleles on one chromosome of a pair?