Transcript Slide 1
Your genome:
What does your DNA say about you?
Personal Genetics Education Project (pgEd) Harvard Medical School www.pged.org
personal genetics education project
http://www.flickr.com/photos/barl0w/3036412907 • Our
genome
is our unique code of DNA that carries the information that affects our traits, including our appearance, behavior, and health.
• Each of us inherited half of our genome from our mother and half from our father, and this is why we often share traits with our parents.
• As a result, siblings that share parents often share traits.
personal genetics education project
http://www.flickr.com/photos/publik15/3298691800 • DNA is a chemical made up of a chain of
bases.
bases – A, C, G and T.
There are 4 types of • In humans, our genome consists of ~3 billion bases.
• Chains of bases are called
chromosomes
. The number of chromosomes and the order of bases along each chromosome are very important.
• Each chromosome carries segments of DNA, known as
genes
, that are the blueprints to make proteins.
personal genetics education project
http://www.flickr.com/photos/edyson/38312588 • In general, we each have 23 pairs of chromosomes. One chromosome from each pair comes from our mother and one from our father.
• Therefore, in general, we inherit two copies of each gene. Our genomes contain approximately 20,000 genes. • Genome sequencing determines the order of the 3 billion bases of our genome and can reveal information about our traits.
Genetic diversity
Our genomes are over 99% identical Remaining <1% difference =>
GENETIC VARIATION
personal genetics education project
Genetic diversity
Our genomes are over 99% identical Remaining <1% difference =>
GENETIC VARIATION
Terminology: How do we talk about our genetic differences?
MUTATIONS VARIANTS
personal genetics education project
Genetic diversity
Our genomes are over 99% identical Remaining <1% difference =>
GENETIC VARIATION
Terminology: How do we talk about our genetic differences?
MUTATIONS VARIANTS
personal genetics education project
Pedigrees depict family history
Example: A family where a trait appears in 2 out of 3 children
Dad Mom Son (unaffected) Twin son (affected) Twin daughter (affected) personal genetics education project
Joe
Pedigrees represent families – the Beerys
Retta Zach Noah Alexis http://www.nature.com/news/2011/110615/full/news.2011.368.html
personal genetics education project
Pedigrees depict family history
Example: A family with inherited breast cancer susceptibility (BRCA1 variant)
Steven age 60 breast cancer Maria Vanessa Emily Angela Malcolm XX Chris Ashley personal genetics education project
Pedigrees depict family history
Example: A family with inherited breast cancer susceptibility (BRCA1 variant)
Steven age 60 breast cancer Maria Vanessa age 55 breast cancer Emily Angela age 45 ovarian cancer Malcolm XX Chris Ashley age 32 surgery Chloe Justin personal genetics education project
A major goal of genetics research is to understand the relationship between
your DNA
and
your traits
?
http://www.flickr.com/photos/wellcomeimages/ 5814818738/sizes/l/in/photostream/ http://www.flickr.com/photos/w4nd3rl0st/6789227039
Appearance Behavior Health
personal genetics education project
Even identical twins are different:
DNA alone does not determine who we are
http://www.flickr.com/photos/wellcomeimages/ 5814818738/sizes/l/in/photostream/ http://www.flickr.com/photos/barl0w/3036412907
Environment and Social Factors
http://www.flickr.com/photos/w4nd3rl0st/6789227 039
Appearance Behavior Health
personal genetics education project
Complex relationship between our DNA and the environment
DNA alone does not determine who we are
http://www.flickr.com/photos/wellcomeimages/ 5814818738/sizes/l/in/photostream/ Examples:
PKU (phenylketonuria):
A genetic disease with an environmental cure (diet)
Inherited cancer susceptibility:
Women with same BRCA1 variant differ in whether they develop cancer, type of cancer, and age of onset Type 2 Diabetes: Common disease with environmental and genetic contributions. http://www.flickr.com/photos/barl0w/3036412907
Environment and Social Factors
personal genetics education project
DNA: Your personal health risk forecast
1.
A weather forecaster makes predictions about if it will rain.
• Your DNA makes predictions about you (i.e. what is your risk for disease?) It is not a guarantee.
personal genetics education project
DNA: Your personal health risk forecast
1.
A weather forecaster makes predictions about if it will rain.
• Your DNA makes predictions about you (i.e. what is your risk for disease?) It is not a guarantee.
1.
The forecast might be <10% chance of rain, a 30% chance, or a 90% chance. And weather forecasts often change based on new information.
• In some cases, your DNA might suggest a strong risk of disease. For other diseases, your risk might be lower. As new risk factors are found, these numbers might change. personal genetics education project
DNA: Your personal health risk forecast
1.
A weather forecaster makes predictions about if it will rain.
• Your DNA makes predictions about you (i.e. what is your risk for disease?) It is not a guarantee.
1.
The forecast might be <10% chance of rain, a 30% chance, or a 90% chance. And weather forecasts often change based on new information.
• In some cases, your DNA might suggest a strong risk of disease. For other diseases, your risk might be lower. As new risk factors are found, these numbers might change. 3.
How does the forecast affect whether you’d go out? Or whether you’d bring an umbrella?
• With a 90% chance of rain, you might decide to stay in. With a 50% chance, maybe you would decide to go out but bring an umbrella. The probability that you will develop a disease may influence the choices that you make.
personal genetics education project
DNA: Your personal health risk forecast
1.
A weather forecaster makes predictions about if it will rain.
• Your DNA makes predictions about you (i.e. what is your risk for disease?) It is not a guarantee.
1.
The forecast might be <10% chance of rain, a 30% chance, or a 90% chance. And weather forecasts often change based on new information.
• In some cases, your DNA might suggest a strong risk of disease. For other diseases, your risk might be lower. As new risk factors are found, these numbers might change. 3.
How does the forecast affect whether you’d go out? Or whether you’d bring an umbrella?
• With a 90% chance of rain, you might decide to stay in. With a 50% chance, maybe you would decide to go out but bring an umbrella. The probability that you will develop a disease may influence the choices that you make.
4. Sometimes it rains when the forecast expects <10% chance of rain. • If your risk for disease is >90%, this still means 10 people out of 100 on average will not develop the disease. If your risk is 1%, 1 person in 100 is expected to get sick.
personal genetics education project
DNA: Your personal health risk forecast
1.
A weather forecaster makes predictions about if it will rain.
• Your DNA makes predictions about you (i.e. what is your risk for disease?) It is not a guarantee.
1.
The forecast might be <10% chance of rain, a 30% chance, or a 90% chance. And weather forecasts often change based on new information.
• In some cases, your DNA might suggest a strong risk of disease. For other diseases, your risk might be lower. As new risk factors are found, these numbers might change. 3.
How does the forecast affect whether you’d go out? Or whether you’d bring an umbrella?
• With a 90% chance of rain, you might decide to stay in. With a 50% chance, maybe you would decide to go out but bring an umbrella. The probability that you will develop a disease may influence the choices that you make.
4. Sometimes it rains when the forecast expects <10% chance of rain. • If your risk for disease is >90%, this still means 10 people out of 100 on average will not develop the disease. If your risk is 1%, 1 person in 100 is expected to get sick.
5. Does the forecast predict how hard it will rain?
• Even for a disease like cystic fibrosis, the severity of symptoms vary for individuals with the same variant in the CFTR gene (due to additional genetic and environmental factors).
personal genetics education project
There are multiple ways to express a 1 in 10 risk
1 in 10 people
10% risk 3 students in your class (of 30) 3-fold lower risk, assuming the population risk is 3 in 10 personal genetics education project
For more information, please visit us at www.pged.org
personal genetics education project