Flashcards in DNA Analysis and Sudden Death Deck (15)
What is meant by penetrance?
Likelihood of getting the disease if you have the mutation
=> 100% penetrance means you will always get the disease if you have the mutation
What is meant by Mendelian disorders?
Disease caused by a single gene mutation
Rare in population but has High penetrance
What is Next Generation Sequencing used for?
Analysis of multiple genes
- sequences small sections at a time
- lines these up to other gene copy to look for homo/heterozygous mutations
What is central dogma used for?
- predicts what certain mutations will do to a gene
=> whether or not it will affect end result
What could a change in the gene potentially be?
- disease causing mutation
- variant of unknown significance
How is data filtered in order to find the causative mutation?
- Sequence from exome
- Keep variations in right genes
- Keep variations expected to affect gene (stops, frame shifts etc.)
- Keep variations NOT listed as polymorphisms`
What can cause a change in the splice junction of a gene?
mutation in the first few bases of an intron
How would you describe this mutation:
Methionine in position 157 of the peptide (p.) sequence of SMAD4 gene has mutated to Threonine
What does "c." in a mutation description mean?
part of cDNA strand
(mature mRNA with introns removed before translation)
What causes of sudden death may have genetic components?
MI - familial hypercholesterolaemia
Aortic dissection - Marfans, Loeys Dietz
Genetic causes of Aortic dissection usually have problems in the same signalling pathway. TRUE/FALSE?
- e.g FIbrillin affected in MArfans
- TBR1 or TBR2 in Loeys Dietz
How can patients with Loeys Dietz beb identified by their phenotype?
wide set eyes
How many genes are known to cause Long QT and how many of these are common?
around 10 known
- 3 common
A mutation causing problems with what receptor results in familial hypercholesterolaemia?
Low density lipoprotein receptor