What are genes?
Genes are segments of DNA that contain instructions for building the molecules that make
the body work. Most of the molecules are proteins. Parents pass their genes to their
offspring.
What is a genome?
A genome is all of the genetic material in an organism. It is made of DNA (or RNA in some
viruses) and includes genes and other elements that control the activity of those genes.
Does everybody have the same genome?
The human genome is mostly the same in all people. But there are variations across the
genome. This genetic variation accounts for about 0.001 percent of each person's DNA and
contributes to differences in appearance and health. People who are closely related have
more similar DNA.
Some of the variations between individuals result from epigenetic changes. These changes DNA is shaped like a
corkscrew-twisted ladder,
arise from chemical tags that attach to DNA and affect how cells read DNA’s instructions.
called a double helix. The two
Epigenetic changes can be inherited. ladder rails are referred to as
backbones, and the rungs are
Is genetic variation related to health and disease? pairs of building blocks called
bases. Humans have about 3
Many differences in DNA have no effect on health or disease risk. But some do. Because billion base pairs in each cell.
parents pass their genes on to their offspring, some diseases tend to cluster in families, Credit: NIGMS.
similar to other inherited traits. Genetic variations can influence how people respond to
certain medicines as well.
What does it mean to have a genetic risk?
Having a genetic risk means that a person has inherited the tendency to develop a certain illness. It does not
mean that he or she will definitely develop the illness. Rather, it means there is a higher chance of developing
it than if he or she did not have the risk.
What can a genetic test reveal?
A genetic test can identify genetic variations that studies have linked
to the risk of developing a specific disease or of passing a disease gene
on to descendants. A genetic test can also indicate how a person
might respond to certain medicines.
Why does genetic research sometimes involve specific
population groups?
Population groups often include people with the same ancestry and
The ability to determine the precise order of therefore very similar genomes. Plus, populations may share diets,
bases that make up DNA is speeding environments and other characteristics that influence health. These
biomedical research. Credit: Stock image. genetic and environmental similarities make it easier for scientists to
Studying Genes ● August 2017 ● Page 1
Genes are segments of DNA that contain instructions for building the molecules that make
the body work. Most of the molecules are proteins. Parents pass their genes to their
offspring.
What is a genome?
A genome is all of the genetic material in an organism. It is made of DNA (or RNA in some
viruses) and includes genes and other elements that control the activity of those genes.
Does everybody have the same genome?
The human genome is mostly the same in all people. But there are variations across the
genome. This genetic variation accounts for about 0.001 percent of each person's DNA and
contributes to differences in appearance and health. People who are closely related have
more similar DNA.
Some of the variations between individuals result from epigenetic changes. These changes DNA is shaped like a
corkscrew-twisted ladder,
arise from chemical tags that attach to DNA and affect how cells read DNA’s instructions.
called a double helix. The two
Epigenetic changes can be inherited. ladder rails are referred to as
backbones, and the rungs are
Is genetic variation related to health and disease? pairs of building blocks called
bases. Humans have about 3
Many differences in DNA have no effect on health or disease risk. But some do. Because billion base pairs in each cell.
parents pass their genes on to their offspring, some diseases tend to cluster in families, Credit: NIGMS.
similar to other inherited traits. Genetic variations can influence how people respond to
certain medicines as well.
What does it mean to have a genetic risk?
Having a genetic risk means that a person has inherited the tendency to develop a certain illness. It does not
mean that he or she will definitely develop the illness. Rather, it means there is a higher chance of developing
it than if he or she did not have the risk.
What can a genetic test reveal?
A genetic test can identify genetic variations that studies have linked
to the risk of developing a specific disease or of passing a disease gene
on to descendants. A genetic test can also indicate how a person
might respond to certain medicines.
Why does genetic research sometimes involve specific
population groups?
Population groups often include people with the same ancestry and
The ability to determine the precise order of therefore very similar genomes. Plus, populations may share diets,
bases that make up DNA is speeding environments and other characteristics that influence health. These
biomedical research. Credit: Stock image. genetic and environmental similarities make it easier for scientists to
Studying Genes ● August 2017 ● Page 1
