About genetic diseases

Getting to know mutations

You recently discovered what genes are and how they work. What happens when there are changes to genes? To answer this question, we have to explore mutations.

What are mutations?

Mutations are changes in our genes that can lead to missing, incorrect, or extra information. Remember that your genes are like an instruction manual. If the manual is missing a page, or has added or incorrect information, things may not work properly. The same is true for your body.

Sometimes mutations make it hard for your body to build proteins that allow it to function as it should. When this happens, genetic disease may occur.

Ripped-up manual representing how  genes can lead to incorrect  information

What causes mutations?

At first, we might think of mutations as something that will make us sick, but that isn’t always the case. Mutations are a common and natural part of life. They happen for different reasons, and they can be inherited or noninherited.

Family tree, parent, and child illustration to  represent inherited nature of mutations

Inherited mutations: passed down

Inherited mutations are passed down from one or both birth parents. They may also be passed to your own children. They can travel through several generations.

Hemophilia is an example of an inherited mutation.

Buildings, sun, and factory graphics with smoke to represent mutations caused by environmental factors

Noninherited mutations: not passed down

Noninherited mutations happen unexpectedly from things you come into contact with or from health choices.

Certain cancers are caused by environmental factors and are noninherited mutations.

Genetic diseases caused by mutations

Genetic mutations cause anywhere from 5000 to 8000 genetic diseases. Many of these diseases result in serious health problems.

Some diseases already have therapies that can help. The possibilities for treatments continue to grow as we learn more about these conditions.

We can break genetic disorders down into 3 types:

Single gene

Single-gene disorders occur when there is a mutation in only 1 gene. Cystic fibrosis is an example of a single-gene disorder.


A chromosomal disorder can happen when there is an extra or missing chromosome. It can also occur if there is a change to part of a chromosome. Down syndrome is an example of a chromosomal disorder.


Complex disorders happen when there is a change, or mutation, in more than 1 gene. Type 2 diabetes is an example of a complex disorder.

Mutations within the genes can lead to genetic disease. Let’s learn more about how gene therapy works in the body.

Get more on gene therapy

Learn more

Sign up to receive the latest resources direct to your inbox.

Sign up