Lecture 18: Human Genetic Disease File Flashcards
What does the cystic fibrosis gene encode ?
encodes cyclic AMP regulated chloride ion channel (found in apical membranes of secretary epithelial cells)
What do mutations in CTRF disrupt ?
they disrupt the epithelial ion transport and can lead to respiratory failure and pancreatic insufficiency.
Impaires cells ability to transport chloride ions in and out of the cell
Where is the CF gene found ?
chromosome 7
75% of CF mutation are …..?
deltaF508
25% of CF mutations are….?
SNP’s
Once an SNP is known, it can easily be detected using which approach ?
PCR approach
Describe PCR approach in terms of molecular detection of SNP’s
- Design pair of primers that stop next to known SNP
- add flourescent labelled ‘terminator’ bases
- Identify which single fluorescent nucleotide is incorporated
What type of disorder is Myotonic dystrophy ?
anticipation disorder
Whats the correlation between the CTG repeat and the severity of myotonic dystrophy ?
more repeats = more severe
Myotonic dystrophy only affects ____?
mRNA
How does myotonic dystrophy occur ?
Myotonic dystrophhy mRNA forms ‘stem-loop’ structure which binds to essential components of splicing machinary. Large repeats ‘mop-up’ these essential components which causes mis-splicing of other genes
WHere is HD mutation?
dominant mutation on chromosome 4
What type of disorder is HD ?
anticipation disorder
What is the repeat in HD and what does it encode ?
CAG, encodes poly glutamine in huntingtin protein
What is the cause of HD ?
expression of polyQ within other genes
