Genetics Flashcards
Why is DNA suspectible to damage?
DNA replication is error prone
What is meiosis
Diploid parent = 4 haploid daughter cells
Variant vs mutuation
Variant = change in DNA sequence Mutuation = any heritable change (not always disease causing)
Define polymorphism
variation in human genome with pop. frequency >1%
OR
variant that does not cause disease in its own right
When does cells in the body acquire somatic (non-inherited) mutations?
During mitosis
Define mosaicism
Different cells have different genetic constitution
LOOK more at this
What is the more common type of CGH (comparative genomic hybridisation)
Array CGH - sample is fragmented ahead of hybridisation
Karyotyping is still regularly used?
False
Where is FISH used?
Only really for rare cancers
Define penetrance - IMPORTANT
Likelihood of having the disease if you have a mutation
What is BRCA and HER2 associated with?
Breast cancer
What is the first genetic test used when looking for chromosomal imbalance?
Array CGH
When is PCR and sequencing used?
When looking for point mutations
What is NGS (next generation sequencing) most useful for?
Looking at many genes for mutations
How many bases code 1 AA?
Why is this very important?
3
Missing AA -> mutations
Define mutation?
Genetic variation that is likely to cause disease
Define polymorphism
Is it disease causing?
Genetic change that causes in >1% of the population
Predisposes you to disease
Nonsense
Missense
Silent
Frame-shift
Explain the above ^^^
Nonsense - stop codon
Missense - change AA
Silent - different codon, same AA
Frame-shift - addition/deletion of base
Unambigious vs degenerate
Unambigious - each codon = 1 AA
Degenerate - AAs have many codons
