Understanding Gene Replacement Therapy for Genetic Diseases

What is a genetic disease?

A genetic disease is caused by a nonworking or missing gene or genes. A genetic disease can be passed down from one or both parents or can be a result of random errors in the body’s genes.

What is a monogenic disease?

A monogenic disease is a disease caused by a single, nonworking or missing gene or gene pair. Gene replacement therapy is being studied for monogenic diseases, as the function of only one gene needs to be fixed.

Learn more about monogenic diseases.
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What is the goal of gene replacement therapy?

Usually a person’s own genes do their jobs to produce specific proteins.

In a person with a monogenic disease, there is one gene that is missing or does not work right. This results in the protein being made incorrectly, made in short supply, or not made at all.

The goal of gene replacement therapy is to give the body a new, working copy of the missing or nonworking gene. This new gene may or may not become part of a person’s DNA and is able to give the body instructions for making a particular protein the body needs.

Usually a person’s own genes each do their job to produce specific proteins.

Person without a monogenic disease

A diagram of the genes of a person without a monogenic disease

In a person with a monogenic disease, there is one gene that is missing or does not work right. This results in either the protein being made incorrectly, made in short supply, or not made at all.

Person with a monogenic disease

A diagram of the genes of a person with a monogenic disease

The goal of gene replacement therapy is to give the body a new working copy of the missing or faulty gene. This new gene may or may not become part of a person’s DNA and is able to give the body instructions for making a particular protein the body needs.

Person treated with gene replacement therapy

A diagram of the genes of a person with gene replacement therapy

Check your understanding of gene replacement therapy

Q&A

How does gene replacement therapy aim to treat genetic diseases?

Gene replacement therapy uses a new, working gene to treat or prevent genetic diseases. This new gene provides the body with instructions for making the protein that was missing or in short supply.

Learn how gene replacement therapy works.