Genetics Flashcards
What is penetrance?
likelihood of having a disease if you have the mutation
What is the best test for high penetrance conditions?
genetic testing
What does 100% penetrance mean?
you’ll 100% get the disease
What are Mendalian disorders?
disease caused by a change in a single gene
often have high penetrance
What sort of inheritance do the genes for dissecting aortic aneurysms have?
autosomal dominant
What is the first line test for familial hypercholesteraemia?
test cholesterol levels
What things mean you definitley have familial hypercholesteraemia?
total cholesterol >7.5mmol or LDL >4.9mmol/l
tendon xantheomas in the patient or in a 1st/2nd degree relative
DNA based evidence of a mutation in LDLR, APOB or PCSK9
What things may mean that you have familial hypercholesteraemia?
FH of premature MI <50 in 2nd degree relative and <60 in 1st
FH of elevated total cholesterol >7.5mmol/l
Who is more likely affected in X linked dominant conditions?
females
Who is more likely affected in X linked recessive conditions?
males
What gender can only pass on mitochondrial diseases?
females
Why is a mutation more likely to be pathogenic?
if it is an exon - therefore the protein expressed will change
How do you need to exclude long QT syndrome?
3 ECGs, 3 weeks apart
