Genetic Risks Flashcards
What are the aims of using genetics to assist population health?
- Genetic screening can detect individuals at increased risk of disease.
- Genetic information will promote a healthy lifestyle (increases life longevity and quality of life)
- Establish clear diagnostic boundaries
- Knowing genetic risk will prevent disease onset
- Develop new and more ‘targeted’ medications
- Personalised treatment plans that will work for your genes
What is DNA composed of?
- a deoxyribose sugar
- a base
What is a chromosome?
A continuous piece of DNA.
How many genes do humans have?
20,000 - 30,000
What are genes’ purposes?
To code for specific proteins
List a few types of genetic mutation.
- Duplication of a gene
- Deletion of a gene
- Inversion of a gene
What is a single-gene disease?
Inherited diseases that are caused by a mutation in a single gene
Give an example of a single gene disease and describe it.
Cystic Fibrosis.
A genetic disease that causes long-term lung infections and limits the ability to breathe over time, is caused by variants in the cystic fibrosis transmembrane conductance regulator(CFTR)gene on chromosome 7.
What is a complex (polygenic) disease?
Diseases that occur as a result of many genomic variants, paired with environmental influences such as diet and smoking.
Give an example of a complex disease.
Coronary artery disease.
Define ‘genetic predisposition’.
An increased likelihood of developing a particular disease based on a person’s genetic makeup.
List four types of methods used to measure population health using genetics.
- Family based studies
- Linkage studies
- Expression
- Association analyses
What is the purpose of family based studies?
To identify how heritable an outcome is.
How do researchers carry out family based studies?
- Twin studies which are conducted on identical or fraternal twins. They aim to reveal the importance of environmental and genetic influences for traits, phenotypes, and disorders.
- Adoption studies are used to estimate the degree to which variation in a trait is due to environmental and genetic influences.
What is linkage analysis?
A statistical method for mapping the genes for heritable traits to their chromosome locations.
What is the candidate-gene approach?
Depends on a set of genetic markers based on a prior hypothesis about the role of a selected gene, or a group of pathway-related genes, on a phenotype.
List a few difficulties with succeeding in candidate-gene approaches.
1) small sample sizes
2) inadequate or loose statistical thresholds
3) inefficient number of genetic markers tested
4) people dropping out of the study
List the issues with the Genome-Wide Association Studies (GWAS).
Not representative of those who are not of European ancestry.
What is a polygenic score (PGS)?
PSG condenses condenses information from many of a person’s genetic variants into a score that measures the individual’s genetic predisposition to specific diseases or complex traits.
What does SNP stand for?
Single-nucleotide polymorphisms
How are SNPs used to predict disease risk?
Merging information across thousands or even millions of SNPs can be useful in predicting disease risk.
