T6: Genetic Disease

Question 1

Genetic Disease

Answer 1

disease with a simple genetic contribution

alleles associated have high penetrance

Question 2

Penetrance

Answer 2

proportion of individuals with genotype that exhibit that phenotype

Question 3

Most diseases / phenotypes

Answer 3

caused by many loci of minor effect - causing major change

Question 4

GWAS

Answer 4

genome-wide association studies

Question 5

Founder effects

Answer 5

type of genetic drift where a small group of individuals starts a new population causing minimal genetic diversity

ex. myotonic dysotrophy

Question 6

inefficient selection

Answer 6

• bad at purging rare recessive alleles
• bad at purging deleterious alleles that affect late-life (even dominant ones)

Question 7

GDs persist because of

Answer 7

-founder effects
-inefficient selection
-fitness benefit (heterozygote advantage or through pleiotrophy)

Question 8

Tay Sachs disease

Answer 8

degenerative neurological condition
- recessive mutations (encodes lysosomal enzyme)
carrier freq= 1/275
higher for french canadian and ashkenazi jewish

Question 9

Cystic fibrosis

Answer 9

lung fxn and growth
recessive mutations
lots of carriers NS and PEI

Question 10

Huntington’s disease

Answer 10

late-life onset
fatal brain disorder
single dominant allele

have more tp53 and reproduce more
heterozygote advantage

Question 11

Heterozygote advantage

Answer 11

ex. sickle cell anemia/ malaria

fitness benefit to having an allele