Inherited and Acquired mutations

Inherited mutations

Most genes come in pairs. One copy of each gene comes from your mother and one copy from your father. Sometimes, a parent may pass a gene with damage called a "mutation" to one or more of their children. The children with this mutation can pass it to each of their children. A gene mutation that is passed from a parent to their child is called an "inherited mutation." Depending on which gene has the damage, inherited mutations can increase your risk for certain conditions or diseases, like cancer. You can view our video: how mutations cause cancer and read more on our page How Are Mutations Inherited?

An inherited gene mutation does not always cause cancer. If you inherit a mutation from your father, you still have a normal copy of the same gene from your mother.

Acquired mutations 

Cell damage can also be acquired. "Acquired" mutations happen after a person is born. They are caused by “wear and tear” on genes over time. Some causes of  acquired mutations include:

• aging
• exposure to hormones
• exposure to toxins in your environment
• certain viruses

Damage that builds up in cells can lead to cancer.

People with inherited mutations are born with one already damaged gene in all of the cells in their body. This means fewer steps are needed for their cells to develop cancer. 

DNA damage repair

Cells have tools to repair DNA damage. If it cannot be repaired, the body has ways to remove the damaged cell so that it cannot divide and create more damaged cells. This system isn't always perfect, and DNA damage and gene mutations can build up in cells. Over time, this can lead to cancer. 

• Cancers in people who do not have an inherited mutation are called "sporadic" cancers.
• Cancers in people who do have an inherited mutation are called "hereditary" cancers. 
   

DNA damage repair genes

Certain genes are important for repairing DNA damage. These genes are sometimes referred to as "DNA damage repair" or "DDR" genes. 

• In normal cells, mutations in DNA damage repair genes increase the chance that the cell will become cancer. This is why inherited mutations in genes that repair DNA damage increase the risk for cancer.
• In cells that are already cancerous, mutations in DNA damage repair genes can keep the cells from repairing damage caused by treatment. This means that cancer cells with mutations in these genes may be more sensitive to certain treatments.