Genetics in Medical Research Flashcards
Definition of pleitropy
genetic effect of 1 gene on many phenotypic traits
Definition of genetic modifiers
Genes that affect phenotype/molecular expression of other genes
Why can we use genetics clinically
What can we do with genetics clinically
Cheaper to sequence genomes
Increased availability of testing
Identify disease related genes
Identify effect size of different loci
Identify treatable diseases earlier
Why are genetic diagnoses important
Insight into drug responses
Molecular diagnoses used for
-preimplantation genetic diagnoses
-can make important life decisions
Describe the different genetic variants that can be found and their effect size
Rare alleles -highly penetrant disease -v large effect size OR -small/unknown effect size
More common alleles
-moderate risk and effect size
Most common alleles
-low risk and effect size
Variants can also be associated with pleiotropy
How could we use polygenic risk scores in the future
What other info would we need for PRS to be useful
The inheritance of many low risk variants when summed together => significant increased risk
Polygenic risk score + clinical risk => combined risk
Can be used as a good predictor of disease in later life
Describe how tandem repeats can be a significant contributor to disease
How are they detected
Generally mutate more rapidly than SNPs
Long read sequencing allows for detection and quantification
Important disease mechanism for genes associated with neurological disease
Describe pleiotropy and its effects
1 gene => many phenotypic traits
Many disease have several genes in common
Describe the 5 factors that must be met for a disease to be considered familial
Family size must be large enough
Phenotype must be consistent
Not associated with undue stigma (not hidden from other family members)
Proband must be in contact with family
Need to have reached age of risk
How can you accidently interpret an illness as sporadic
If illness is
- late onset
- incomplete penetrance
What are genetic modifiers
How can polygenic disorders affect penetrance of monogenic variants
Genes that affect phenotypic/molecular expression of other genes
Polygenic disorders can modify penetrance of monogenic variants
What are the 3 possible treatments for HD
What do they aim to target
DNA targeting
RNA targeting
Protein targeting
Target molecules throughout transcription, translation
What are the 2 risks of genetic testing
Reveals the truth about your ancestry and parentage
Attitudes to genetic data usage and sharing
