BRCA1, familial breast-ovarian cancer susceptibility 1
What is Hereditary Breast and Ovarian Cancer syndrome caused by BRCA1 gene mutations?
Hereditary Breast and Ovarian (HBOC) syndrome is a cancer condition caused by genetic changes in the BRCA1 or BRCA2 genes. Genetic changes in these genes can be passed from parent to child. In other words, HBOC syndrome runs in families. HBOC syndrome is the most common cause of both hereditary breast and hereditary ovarian cancer. People with a genetic change in a BRCA1 or BRCA2 gene have an increased risk for certain types of cancers, including breast, ovarian, prostate, and pancreatic cancers and melanoma. Both men and women can have HBOC syndrome.
Additional and accurate information about HBOC can be found on specific websites including:
1. The "Facing Our Risk of Cancer Empowered" (FORCE) advocacy group's resources for people living with an increased risk of HBOC on their Understanding BRCA and HBOC website.
2. For healthcare providers, an expert summmary on HBOC can be found on the GeneReviews for HBOC.
- Geneclinics "HBOC" www.ncbi.nlm.nih.gov/books/NBK1247/
- FORCE "Understanding HBOC" http://www.facingourrisk.org/understanding-brca-and-hboc/index.php
More Overview Content
Are there other names for Hereditary Breast and Ovarian Cancer syndrome?
Hereditary Breast and Ovarian Cancer (HBOC) syndrome is also known as BRCA-Related Breast and/or Ovarian Cancer syndrome. HBOC syndrome is often referred to by using the names of the genes associated with this condition. These genes include BRCA1 and BRCA2. Sometimes the two gene names are combined together to BRCA1/2, or simply referred to as BRCA. Some people also call BRCA1 and BRCA2 the "BRACA" genes. BRACA was the name of one of the first genetic tests to look at the BRCA1 and BRCA2 genes.
How common is Hereditary Breast and Ovarian Cancer syndrome caused by BRCA1 gene mutations?
Hereditary Breast and Ovarian Cancer syndrome is the most common cause of both hereditary breast and hereditary ovarian cancer. Less than 1% of the general population (1 in 400 people) has a genetic change, or mutation, in BRCA1/2, which causes HBOC syndrome. BRCA1/2 mutations are more common in individuals of Ashkenazi Jewish ancestry. More specifically, around 2.5% of people from the Ashkenazi Jewish population (1 in 40 people) carry a BRCA1/2 mutation.
Do other diseases that look a lot like Hereditary Breast and Ovarian Cancer syndrome?
Hereditary Breast and Ovarian Cancer syndrome is caused by mutations, or genetic changes, in either the BRCA1 or BRCA2 genes. There are also other hereditary breast cancer syndromes. For example:
- Li-Fraumeni syndrome (TP53 gene) increases the risk for multiple cancers including breast, sarcoma, brain, adrenocortical carcinoma, and other cancers
- Cowden syndrome (PTEN gene) increases the risk for breast, thyroid, uterine, kidney, and other cancers
- Hereditary Diffuse Gastric Cancer syndrome (CDH1 gene) increases the risk for breast, stomach, and colorectal cancer
- Peutz-Jeghers syndrome (STK11 gene) increases the risk for breast, colorectal, stomach, small bowel, pancreatic, and other cancers
There are other genes, referred to as moderately penetrant genes, that are also associated with hereditary breast and/or hereditary ovarian cancer. Although moderate penetrance genes are associated with hereditary cancer, the cancer risks are not as high when compared to genes such as BRCA1/2. Moderate penetrance genes associated with an increased risk for breast and other cancers include genes such as ATM, CHEK2, and PALB2. Genes such as BRIP1, RAD51C, and RAD51D are moderate penetrance genes associated with an increased risk for ovarian and other cancers.