CF - L2 Flashcards Preview

Molecule to Malady > CF - L2 > Flashcards

Flashcards in CF - L2 Deck (14):
1

What is the pattern of inheritance of CFTR and the incidence? and carrier frequency

autosomal recessive
1 in 250,000
1 in 25

2

What does being a carrier have a selective advantage for? (possibly)

cholera (you die from dehydration)
typhus (bacteria uses CFTR to enter cell)
asthma

3

What are typical pedigree traits?

horizontal pattern
de novo mutations rare

4

What phenotype are classes I, II & III usually associated with?

severe lung disease and PI

5

What phenotype are classes IV & V usually associated with?

PS and milder lung disease

6

What is the difference in penetrance of F508del and R117H?

F508del, usually severe PI
R117H, variable

7

What does the penetrance of R117H depend on?

intragenic polymorphism in intron 8 on same allele in cis
R117H & 5T: likely to have disease symptoms
R117H & 7T: unlikely to have disease symptoms
R117H & 9T: highly unlikely for symptoms

8

How do you identify genetic modifiers of CF?

linkage
candidate gene association
GWAS

9

What are some genetic modifiers of lung disease?

EDNRA: probable effect, smooth muscle tone
MBL2: probable effect, innate immunity
TGFB1: probable effect, regulating inflammation and tissue remodelling

10

What are some genetic modifiers of intestinal obstruction?

MSRA: methionine sulphide reductase modifies intestinal enzymes

11

What are some genetic modifiers of diabetes?

TCF7L2: proliferation and function of beta cells

12

What are some environmental modifiers?

female
economic status
tobacco
infectious exposures

13

What types of screening are there for CF?

newborn
cascade
population carrier

14

What are the stages of newborn screening?

IRT levels
DNA testing
If one CF mutation:
sweat test
carrier or CF