What Is the BRCA1 Gene?

In healthy people, genes are efficient at preventing cancerous cells from developing. In some people with breast cancer, important genes in this process are mutated and cannot perform this role properly. The BRCA1 gene is one of the genes that can affect the development of breast cancer, and can pass down through family lines. Although only a small percentage of cases are influenced by inherited genes, women who do have a family history of the disease may find it helpful to undergo a test for the gene.

Cancerous cells multiply abnormally and the body cannot control their growth. Normally, controls are in place to regulate cell growth. These natural control processes are dictated by the products of regulatory genes. The BRCA1 gene is just one of these regulatory genes. As it plays a role in breast cancer, the full name of the gene is breast cancer 1, early onset.

In healthy women, the BRCA1 gene is usually in an efficient form that does its job properly. It contains the information that the body needs to make a protein called simply the BRCA1 protein. This protein helps to fix damage to cellular DNA. This damage occurs during natural cell division, but other stresses like radiation can also cause it. Usually, the damage is not a problem for a healthy woman, and her genes correct the fault.

Women who have a mutation in a BRCA1 gene, or a mutation in another regulatory gene, like BRCA2, may be less able to fix DNA damage. The gene can have more than 1,000 different forms, and only some of these are serious enough for the gene to code for an inefficient protein or no protein at all. Scientists know which mutations are responsible for cancer development, and have developed a test for the presence of these forms of the gene.

As only about five percent of breast cancer cases are caused by BRCA1 mutations, a genetic test is not practical for all women. Instead, only women with a family history of the disease, which indicates the presence of an inherited mutated gene, generally undergo the test. If the test identifies the presence of a mutated gene, then the woman can look at her options to prevent the development of breast cancer, from regular scans to removal of the breast tissue altogether. As at least half of the women with mutations in this gene experience breast cancer at some point during their lives, they may choose the radical options for peace of mind.

On the other hand, some women with affected genes do not develop the cancer. This is due to the fact that cancers are due to a collection of events, where genetic material inside cells turns the cell cancerous. Abnormal BRCA1 genes do not cause the initial development of a cancer cell, but rather allows the cell to multiply after the initial event has occurred. Scientists do know, however, that abnormal copies of the BRCA1 gene do not just play a role in breast cancer, but can also make the development of other cancers, such as cancer of the pancreas, more likely.