formative

Question 1

In the central dogma, which process is most likely to be affected by a mutation that changes the first base in an intron ?

Answer 1

splicing

Question 2

Jane Green is a 27-year old woman with long QT syndrome diagnosed on ECG. Next generation sequencing is used to analyse 6 genes that might be responsible. Several genetic variants are identified in these genes.
Which type of genetic sequence variant is the one most likely to cause the long QT syndrome ?

Answer 2

a premature stop codon in exon 2 on a gene
–> make the biggest difference - v pathogenic

(missense variant in exon 3 of a gene -> doesnt always change it (redundacy i think?)

Question 3

woman with long QT syndrome diagnosed on ECG. Next generation sequencing is used to analyse 6 genes that might be responsible. A genetic variant is identified in the LQT1 gene.
Which piece of evidence would most strongly suggest that this variant is pathogenic ?

Answer 3

The variant is a deletion of a single base in an exon of the gene
-> frameshift mutation

Question 4

James Black is a 31 year old man with Hypertrophic Cardiomyopathy.
Why is Next Generation Sequencing (NGS) better than conventional sequencing as a test to analyse the 8 genes that might be responsible ?

Answer 4

It allows more efficient analysis of multiple genes
-> does genes faster + cheaper

Question 5

how do you correct the QT interval for heart rate ?

Answer 5

(QT Interval) / (Square root R-R interval)

-> as QT shortens, HR increases

Question 6

Aileen White has long QT syndrome.
Which cardiac arrhythmia is she most at risk of ?

Answer 6

Torsades de Pointes
- delayed cardiac repolarisation

Question 7

Mr and Mrs Blue have a newborn baby.
What is the most important piece of advice that will reduce the risk of sudden infant death ?

Answer 7

To put them to sleep on their back

Question 8

Which of the following drugs may be helpful in treating a patient with long QT syndrome

Answer 8

atenolol (avoid sotalol)