Lecture 24: The Human Genome and disease

Question 1

What does monogenic mean

Answer 1

Inherited by a single gene

Question 2

What are germine mutations

Answer 2

Mutations that can be passed on via the gametes (eggs and sperm)

Question 3

Describe somatic mutations

Answer 3

Mutations acquired by somatic cells if DNA is damaged or copied incorrectly

These are not passed on to the next generation

Question 4

When do dominant mutations cause a phenotype

Answer 4

When heterozygous

Question 5

When do recessive mutations cause a phenotype

Answer 5

When homozygous

Question 6

What is a loss of function mutation

Answer 6

Can break a gene to cause it to not work as well as normal or not at all

Question 7

Are Loss of function mutations normally recessive or dominant?

Answer 7

Recessive, because a normal copy of the gene exists on the other chromosome which can replace the lost function

Question 8

Are Gain of function mutations normally recessive or dominant?

Answer 8

Dominant because having an allele that works too well or does something novel, will not be replaced by the normal copy of the gene

Question 9

Describe the characteristics of Autosomal recessive diseases

Answer 9

Not seen in every generation
Passed on by two asymptomatic carriers
No gender bias shown in likleihood of inheritance

Question 10

Describe the characteristics of Autosomal dominant diseases

Answer 10

Occurs commonly in a pedigree
Affects individuals that have an affected parent
No gender bias shown in likleihood of inheritance

Question 11

Describe the characteristics of X linked Dominant diseases

Answer 11

Most often affect females > males

Question 11

Describe the characteristics of X linked recessive diseases

Answer 11

Fathers cannot pass it to their sons
No male-to-male transmission
Most often affects males

Question 12

What does polygenic mean

Answer 12

disorders involve several genes acting together or environmental factors interacting with genes