DNA Analysis and Sudden Death Flashcards Preview

CLASP - Sudden Death > DNA Analysis and Sudden Death > Flashcards

Flashcards in DNA Analysis and Sudden Death Deck (15)
Loading flashcards...
1
Q

What is meant by penetrance?

A

Likelihood of getting the disease if you have the mutation

=> 100% penetrance means you will always get the disease if you have the mutation

2
Q

What is meant by Mendelian disorders?

A

Disease caused by a single gene mutation

Rare in population but has High penetrance

3
Q

What is Next Generation Sequencing used for?

A

Analysis of multiple genes

  • sequences small sections at a time
  • lines these up to other gene copy to look for homo/heterozygous mutations
4
Q

What is central dogma used for?

A
  • predicts what certain mutations will do to a gene

=> whether or not it will affect end result

5
Q

What could a change in the gene potentially be?

A
  • disease causing mutation
  • polymorphism
  • variant of unknown significance
6
Q

How is data filtered in order to find the causative mutation?

A
  • Sequence from exome
  • Keep variations in right genes
  • Keep variations expected to affect gene (stops, frame shifts etc.)
  • Keep variations NOT listed as polymorphisms`
7
Q

What can cause a change in the splice junction of a gene?

A

mutation in the first few bases of an intron

8
Q

How would you describe this mutation:

SMAD4:p.Met157Thr

A

Methionine in position 157 of the peptide (p.) sequence of SMAD4 gene has mutated to Threonine

9
Q

What does “c.” in a mutation description mean?

A

part of cDNA strand

mature mRNA with introns removed before translation

10
Q

What causes of sudden death may have genetic components?

A

MI - familial hypercholesterolaemia

Aortic dissection - Marfans, Loeys Dietz

11
Q

Genetic causes of Aortic dissection usually have problems in the same signalling pathway. TRUE/FALSE?

A

TRUE

  • e.g FIbrillin affected in MArfans
  • TBR1 or TBR2 in Loeys Dietz
12
Q

How can patients with Loeys Dietz beb identified by their phenotype?

A

wide set eyes
carotid aneurysms
unusual uvula

13
Q

How many genes are known to cause Long QT and how many of these are common?

A

around 10 known

- 3 common

14
Q

A mutation causing problems with what receptor results in familial hypercholesterolaemia?

A

Low density lipoprotein receptor

15
Q

How do patients with familial hypercholesterolaemia usually present?

A

tendon xanthomas

corneal arcus