Human genetics 3 Flashcards
(8 cards)
1
Q
What are some types of single gene disorders?
A
- Mendelian disorders
- inheritance patterns vary with genomic location
- rare but have significant phenotypic consequences
- patterns of single gene inheritance make gene discovery easy
2
Q
What is penetrance
A
The fraction of individuals with a genotype who display symptoms of the disease
3
Q
What is expressivity
A
The severity of disease differs in people with the same genotype
4
Q
What is pleiotropy
A
Single gene disorders
- a single gene may produce multiple mRNAs
- multiple mRNAs may produce multiple proteins
- proteins may act in multiple different systems
A single gene may influence multiple different phenotypic traits
- maybe seemingly unrelated
5
Q
What is Cystic Fibrosis
A
- most common genetic disease in Canada
- normal CFTR channel moves chloride ion to the outside of the cell
- mutant CFTR channels do not move chloride ions, causing sticky mucous to build upon the outside of the wall
6
Q
What is the relationship between Cystic Fibrosis and the lungs
A
Defective chloride pumps lead to less movement of water by osmosis
- water is unable to hydrate the mucus
7
Q
what is ‘delta’F508
A
The most common of over 1900 known mutations
- compound heterozygote
- 2 different mutant alleles at a locus
8
Q
What are the consequences of different mutations in different defective proteins of Cystic Fibrosis
A
- no proteins
- no traffic from the ER to the cell membrane
- no function of the protein
- less function of the protein
- less protein is being created
- less stable
